Virtue

Virtue (Latin: virtus) is moral excellence. 　A virtue is a trait or quality that is deemed to be morally good and thus is valued as a foundation of principle and good moral being. 　In other words, it is a behavior that shows high moral standards: doing what is right and avoiding what is wrong. 　The opposite of virtue is vice. 　Other examples of this notion include the concept of merit in Asian traditions as well as De (Chinese 德). 　Buddhism's four brahmavihara ("Divine States") can be regarded as virtues in the European sense.

Glasses

Glasses, also known as eyeglasses or spectacles, are vision eyewear with lenses (clear or tinted) mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms (known as temples or temple pieces) that rest over the ears. 　Glasses are typically used for vision correction, such as with reading glasses and glasses used for nearsightedness; however, without the specialized lenses, they are sometimes used for cosmetic purposes. 　Safety glasses provide eye protection against flying debris for construction workers or lab technicians; these glasses may have protection on the sides of the eyes as well as in the lenses. 　Some types of safety glasses are used to protect against visible and near-visible light or radiation. 　Glasses are worn for eye protection in some sports, such as squash. 　Glasses wearers may use a strap to prevent the glasses from falling off. 　Wearers of glasses that are used only part of the time may have the glasses attached to a cord that goes around their neck to prevent the loss and breaking of the glasses. 　The loss of glasses would be detrimental to those working in these conditions. 　Sunglasses allow for better vision in bright daylight and may protect one's eyes against damage from excessive levels of ultraviolet light. 　Typical sunglasses lenses are tinted for protection against bright light or polarized to remove glare; photochromic glasses are blacked out or lightly tinted in dark or indoor conditions, but turn into sunglasses when they come into contact with ultraviolet light. 　Most over-the-counter sunglasses do not have corrective power in the lenses; however, special prescription sunglasses can be made. 　People with conditions that have photophobia as a primary symptom (like certain migraine disorders or Irlen syndrome) often wear sunglasses or precision tinted glasses, even indoors and at night. 　Specialized glasses may be used for viewing specific visual information, for example, 3D glasses for 3D films (stereoscopy). 　Sometimes glasses are worn purely for fashion or aesthetic purposes. 　Even with glasses used for vision correction, a wide range of fashions are available, using plastic, metal, wire, and other materials for frames.

Bengal

This article contains Bengali text. 　Without proper rendering support, you may see question marks, boxes, or other symbols. 　Bengal (/bɛnˈɡɔːl/ ben-GAWL; Bengali: বাংলা/বঙ্গ, romanized: Bānglā/Bôngô, pronounced [ˈbɔŋgo] (listen)) is a historical geographical, ethnolinguistic and cultural term referring to the eastern part of the Indian subcontinent at the apex of the Bay of Bengal. 　The region of Bengal proper is divided between modern-day Bangladesh and the Indian state of West Bengal. 　The Indian state of Tripura and the Barak Valley in the Indian state of Assam are also considered part of the Bengali cultural region. 　The administrative jurisdiction of Bengal historically extended beyond the territory of Bengal proper. 　Bengal ceased to be a single unit after the partition of India in 1947. 　Various Indo-Aryan, Dravidian, Austric and other peoples inhabited the region since antiquity. 　The ancient Vanga Kingdom is widely regarded as the namesake of the Bengal region. 　The Bengali calendar dates back to the reign of Shashanka in the 4th century. 　The Pala Empire was founded in Bengal during the 8th century. 　The Sena dynasty ruled between the 11th and 13th centuries. 　By the 14th century, Bengal was absorbed by Muslim conquests in the Indian subcontinent. 　An independent Bengal Sultanate was formed and became the eastern frontier of the Islamic world. 　During this period, Bengal's rule and influence spread to Assam, Arakan, Tripura, Bihar, and Orissa. 　Mughal Bengal later emerged as a prosperous part of the Mughal Empire. 　The last independent Nawab of Bengal was defeated in 1757 at the Battle of Plassey by the British Empire's East India Company. 　The company's Bengal Presidency grew into the largest administrative unit of British India with Calcutta as the capital of India. 　At its peak, the presidency stretched from Burma, Penang, Singapore and Malacca in the east to The Punjab and Ceded and Conquered Provinces in the west. 　Bengal was gradually re-organized by the early 20th century. 　As a result of first partition of Bengal, a short-lived province called Eastern Bengal and Assam existed between 1905 and 1911 with its capital in the former Mughal capital Dhaka. 　Following the Sylhet referendum and votes by the Bengal Legislative Council and Bengal Legislative Assembly, the region was again divided along religious lines in 1947.

Calendar

A calendar is a system of organizing days. 　This is done by giving names to periods of time, typically days, weeks, months and years. 　A date is the designation of a single and specific day within such a system. 　A calendar is also a physical record (often paper) of such a system. 　A calendar can also mean a list of planned events, such as a court calendar or a partly or fully chronological list of documents, such as a calendar of wills. 　Periods in a calendar (such as years and months) are usually, though not necessarily, synchronized with the cycle of the sun or the moon. 　The most common type of pre-modern calendar was the lunisolar calendar, a lunar calendar that occasionally adds one intercalary month to remain synchronized with the solar year over the long term.

Mainland

Mainland is defined as "relating to or forming the main part of a country or continent, not including the islands around it [regardless of status under territorial jurisdiction by an entity]." 　The term is often politically, economically and/or demographically more significant than politically associated remote territories, such as exclaves or oceanic islands situated outside the continental shelf. 　In geography, "mainland" can denote the continental (i.e. non-insular) part of any polity or the main island within an island nation. 　In geopolitics, "mainland" is sometimes used interchangeably with terms like metropole as an antonym to overseas territories. 　In the sense of "heartland", mainland is the opposite of periphery. 　In some language a separate concept of "mainland" is missing and is replaced with a "continental portion". 　The term is relative: in Tasmania, continental Australia is the mainland, while to residents of Flinders Island, the main island of Tasmania is also "the mainland", although the geological Australian continent includes all the former plus the island of New Guinea and all the smaller islands (e.g. the Torres Strait Islands) in between.

Gmina

The gmina (Polish: [ˈɡmʲina], plural gminy [ˈɡmʲinɨ]) is the principal unit of the administrative division of Poland, similar to a municipality. 　As of 1 January 2019[update], there were 2,477 gminas throughout the country, encompassing over 43,000 villages. 　940 gminas include cities and towns, with 302 among them constituting an independent urban gmina (Polish: gmina miejska) consisting solely of a standalone town or one of the 107 cities, the latter governed by a city mayor (prezydent miasta). 　The gmina has been the basic unit of territorial division in Poland since 1974, when it replaced the smaller gromada (cluster). 　Three or more gminas make up a higher level unit called powiat, except for those holding the status of a city with powiat rights. 　Each and every powiat has the seat in a city or town, in the latter case either an urban gmina or a part of an urban-rural one.

Rocket

A rocket (from Italian: rocchetto, lit. 'bobbin/spool') is a vehicle that uses jet propulsion to accelerate without using the surrounding air. 　A rocket engine produces thrust by reaction to exhaust expelled at high speed. 　Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. 　Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere. 　Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. 　Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. 　To control their flight, rockets rely on momentum, airfoils, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity. 　Rockets for military and recreational uses date back to at least 13th-century China. 　Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Moon. 　Rockets are now used for fireworks, missiles and other weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight, and space exploration. 　Chemical rockets are the most common type of high power rocket, typically creating a high speed exhaust by the combustion of fuel with an oxidizer. 　The stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst (monopropellant), two liquids that spontaneously react on contact (hypergolic propellants), two liquids that must be ignited to react (like kerosene (RP1) and liquid oxygen, used in most liquid-propellant rockets), a solid combination of fuel with oxidizer (solid fuel), or solid fuel with liquid or gaseous oxidizer (hybrid propellant system). 　Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. 　However, careful design, testing, construction and use minimizes risks.　[citation needed]

Slope

In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line. 　Slope is often denoted by the letter m; there is no clear answer to the question why the letter m is used for slope, but its earliest use in English appears in O'Brien (1844) who wrote the equation of a straight line as "y = mx + b" and it can also be found in Todhunter (1888) who wrote it as "y = mx + c". 　Slope is calculated by finding the ratio of the "vertical change" to the "horizontal change" between (any) two distinct points on a line. 　Sometimes the ratio is expressed as a quotient ("rise over run"), giving the same number for every two distinct points on the same line. 　A line that is decreasing has a negative "rise". 　The line may be practical – as set by a road surveyor, or in a diagram that models a road or a roof either as a description or as a plan. 　The steepness, incline, or grade of a line is measured by the absolute value of the slope. 　A slope with a greater absolute value indicates a steeper line. 　The direction of a line is either increasing, decreasing, horizontal or vertical. 　A line is increasing if it goes up from left to right. 　The slope is positive, i.e. m > 0 {\displaystyle m>0} . 　A line is decreasing if it goes down from left to right. 　The slope is negative, i.e. m < 0 {\displaystyle m<0} . 　If a line is horizontal the slope is zero. 　This is a constant function. 　If a line is vertical the slope is undefined (see below). 　The rise of a road between two points is the difference between the altitude of the road at those two points, say y1 and y2, or in other words, the rise is (y2 − y1) = Δy. 　For relatively short distances, where the Earth's curvature may be neglected, the run is the difference in distance from a fixed point measured along a level, horizontal line, or in other words, the run is (x2 − x1) = Δx. 　Here the slope of the road between the two points is simply described as the ratio of the altitude change to the horizontal distance between any two points on the line. 　In mathematical language, the slope m of the line is m = y 2 − y 1 x 2 − x 1 . 　{\displaystyle m={\frac {y_{2}-y_{1}}{x_{2}-x_{1}}}.　} The concept of slope applies directly to grades or gradients in geography and civil engineering. 　Through trigonometry, the slope m of a line is related to its angle of inclination θ by the tangent function m = tan ⁡ ( θ ) {\displaystyle m=\tan(\theta )} Thus, a 45° rising line has a slope of +1 and a 45° falling line has a slope of −1. 　As a generalization of this practical description, the mathematics of differential calculus defines the slope of a curve at a point as the slope of the tangent line at that point. 　When the curve is given by a series of points in a diagram or in a list of the coordinates of points, the slope may be calculated not at a point but between any two given points. 　When the curve is given as a continuous function, perhaps as an algebraic expression, then the differential calculus provides rules giving a formula for the slope of the curve at any point in the middle of the curve. 　This generalization of the concept of slope allows very complex constructions to be planned and built that go well beyond static structures that are either horizontals or verticals, but can change in time, move in curves, and change depending on the rate of change of other factors. 　Thereby, the simple idea of slope becomes one of the main basis of the modern world in terms of both technology and the built environment.

Athens

Athens (/ˈæθɪnz/ ATH-inz; Greek: Αθήνα, romanized: Athína [aˈθina] (listen); Ancient Greek: Ἀθῆναι, romanized: Athênai (pl.) [atʰɛ̂ːnai̯]) is a coastal city in the Mediterranean and is both the capital and largest city of Greece. 　With a population close to four million, it is also the seventh largest city in the European Union. 　Athens dominates and is the capital of the Attica region and is one of the world's oldest cities, with its recorded history spanning over 3,400 years and its earliest human presence beginning somewhere between the 11th and 7th millennia BC. 　Classical Athens was a powerful city-state. 　It was a centre for the arts, learning and philosophy, and the home of Plato's Academy and Aristotle's Lyceum. 　It is widely referred to as the cradle of Western civilization and the birthplace of democracy, largely because of its cultural and political influence on the European continent—particularly Ancient Rome. 　In modern times, Athens is a large cosmopolitan metropolis and central to economic, financial, industrial, maritime, political and cultural life in Greece. 　In 2021, Athens' urban area hosted more than three and a half million people, which is around 35% of the entire population of Greece.　[citation needed] Athens is a Beta-status global city according to the Globalization and World Cities Research Network, and is one of the biggest economic centers in Southeastern Europe. 　It also has a large financial sector, and its port Piraeus is both the largest passenger port in Europe, and the third largest in the world. 　The Municipality of Athens (also City of Athens), which actually constitutes a small administrative unit of the entire city, had a population of 637,798 (in 2021) within its official limits, and a land area of 38.96 km2 (15.04 sq mi). 　The Athens Metropolitan Area or Greater Athens extends beyond its administrative municipal city limits, with a population of 3,722,544 (in 2021) over an area of 412 km2 (159 sq mi). 　Athens is also the southernmost capital on the European mainland and the warmest major city in continental Europe with an average annual temperature of up to 19.8 °C (67.6 °F) locally. 　The heritage of the Classical Era is still evident in the city, represented by ancient monuments, and works of art, the most famous of all being the Parthenon, considered a key landmark of early Western civilization. 　The city also retains Roman, Byzantine and a smaller number of Ottoman monuments, while its historical urban core features elements of continuity through its millennia of history. 　Athens is home to two UNESCO World Heritage Sites, the Acropolis of Athens and the medieval Daphni Monastery. 　Landmarks of the modern era, dating back to the establishment of Athens as the capital of the independent Greek state in 1834, include the Hellenic Parliament and the so-called "Architectural Trilogy of Athens", consisting of the National Library of Greece, the National and Kapodistrian University of Athens, and the Academy of Athens. 　Athens is also home to several museums and cultural institutions, such as the National Archeological Museum, featuring the world's largest collection of ancient Greek antiquities, the Acropolis Museum, the Museum of Cycladic Art, the Benaki Museum, and the Byzantine and Christian Museum. 　Athens was the host city of the first modern-day Olympic Games in 1896, and 108 years later it hosted the 2004 Summer Olympics, making it one of the few cities to have hosted the Olympics more than once. 　Athens joined the UNESCO Global Network of Learning Cities in 2016.

Utility

As a topic of economics, utility is used to model worth or value. 　Its usage has evolved significantly over time. 　The term was introduced initially as a measure of pleasure or happiness as part of the theory of utilitarianism by moral philosophers such as Jeremy Bentham and John Stuart Mill. 　The term has been adapted and reapplied within neoclassical economics, which dominates modern economic theory, as a utility function that represents a single consumer's preference ordering over a choice set but is not comparable across consumers. 　This concept of utility is personal and based on choice rather than on pleasure received, and so is specified more rigorously than the original concept but makes it less useful (and controversial) for ethical decisions.

Arch

An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it. 　Arches may be synonymous with vaults, but a vault may be distinguished as a continuous arch forming a roof. 　Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture, and their systematic use started with the ancient Romans, who were the first to apply the technique to a wide range of structures.

Earthquake

An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. 　Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. 　The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. 　The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. 　The word tremor is also used for non-earthquake seismic rumbling. 　At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. 　When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. 　Earthquakes can also trigger landslides. 　In its most general sense, the word earthquake is used to describe any seismic event—whether natural or caused by humans—that generates seismic waves. 　Earthquakes are caused mostly by rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. 　An earthquake's point of initial rupture is called its hypocenter or focus. 　The epicenter is the point at ground level directly above the hypocenter.

Militia

A militia (/mɪˈlɪʃə/) is generally an army or some other fighting organization of non-professional soldiers, citizens of a country, or subjects of a state, who may perform military service during a time of need, as opposed to a professional force of regular, full-time military personnel; or, historically, to members of a warrior-nobility class (e.g. knights or samurai). 　Generally unable to hold ground against regular forces, militias commonly support regular troops by skirmishing, holding fortifications, or conducting irregular warfare, instead of undertaking offensive campaigns by themselves. 　Local civilian laws often limit militias to serve only in their home region, and to serve only for a limited time; this further reduces their use in long military campaigns. 　Beginning in the late 20th century, some militias (in particular officially recognized and sanctioned militias of a government) act as professional forces, while still being "part-time" or "on-call" organizations. 　For instance, the members of United States National Guard units are considered professional soldiers, as they are trained to the same standards as their "full-time" (active duty) counterparts are. 　Militias thus can be either military or paramilitary, depending on the instance. 　Some of the contexts in which the term "militia" can apply include: forces engaged in a defense activity or service, to protect a community, its territory, property, and laws, the entire able-bodied population of a community, town, county, or state available to be called to arms a subset of these who may be legally penalized for failing to respond to a call-up a subset of these who actually respond to a call-up regardless of legal obligation a private (non-governmental) force not necessarily directly supported or sanctioned by a government an irregular armed force that enables its leader to exercise military, economic, or political control over a subnational territory within a sovereign state in Russia and some countries of the former Soviet Union, an official reserve army composed of citizen soldiers known as the militsiya or militia (police) a select militia composed of a small, non-representative portion of the population, maritime militias composed of fishermen and other participants of the marine industry which are organized and sanctioned by a state to enforce its maritime boundaries.

Stranger

A stranger is a person who is unknown to another person or group. 　Because of this unknown status, a stranger may be perceived as a threat until their identity and character can be ascertained. 　Different classes of strangers have been identified for social science purposes, and the tendency for strangers and foreigners to overlap has been examined. 　The presence of a stranger can throw an established social order into question, "because the stranger is neither friend nor enemy; and because he may be both". 　The distrust of strangers has led to the concept of stranger danger (and the expression "don't talk to strangers"), wherein excessive emphasis is given to teaching children to fear strangers despite the most common sources of abduction or abuse being people known to the child.

Playoffs

The playoffs, play-offs, postseason or finals of a sports league are a competition played after the regular season by the top competitors to determine the league champion or a similar accolade. 　Depending on the league, the playoffs may be either a single game, a series of games, or a tournament, and may use a single-elimination system or one of several other different playoff formats. 　Playoff, in regard to international fixtures, is to qualify or progress to the next round of a competition or tournament. 　In team sports in the U.S. and Canada, the vast distances and consequent burdens on cross-country travel have led to regional divisions of teams. 　Generally, during the regular season, teams play more games in their division than outside it, but the league's best teams might not play against each other in the regular season. 　Therefore, in the postseason a playoff series is organized. 　Any group-winning team is eligible to participate, and as playoffs became more popular they were expanded to include second- or even lower-placed teams – the term "wild card" refers to these teams. 　In England and Scotland, playoffs are used in association football to decide promotion for lower-finishing teams, rather than to decide a champion in the way they are used in North America. 　In the EFL Championship (the second tier of English football), teams finishing 3rd to 6th after the regular season compete to decide the final promotion spot to the Premier League.

Chess

Chess is a board game between two players. 　It is sometimes called international chess or Western chess to distinguish it from related games, such as xiangqi (Chinese chess) and shogi (Japanese chess). 　The current form of the game emerged in Spain and the rest of Southern Europe during the second half of the 15th century after evolving from chaturanga, a similar but much older game of Indian origin. 　Today, chess is one of the world's most popular games, played by millions of people worldwide. 　Chess is an abstract strategy game and involves no hidden information. 　It is played on a chessboard with 64 squares arranged in an eight-by-eight grid. 　At the start, each player controls sixteen pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns. 　The player controlling the white pieces moves first, followed by the player controlling the black pieces. 　The object of the game is to checkmate the opponent's king, whereby the king is under immediate attack (in "check") and there is no way for it to escape. 　There are also several ways a game can end in a draw. 　Organized chess arose in the 19th century. 　Chess competition today is governed internationally by FIDE (the International Chess Federation). 　The first universally recognized World Chess Champion, Wilhelm Steinitz, claimed his title in 1886; Magnus Carlsen is the current World Champion. 　A huge body of chess theory has developed since the game's inception. 　Aspects of art are found in chess composition, and chess in its turn influenced Western culture and art, and has connections with other fields such as mathematics, computer science, and psychology. 　One of the goals of early computer scientists was to create a chess-playing machine. 　In 1997, Deep Blue became the first computer to beat the reigning World Champion in a match when it defeated Garry Kasparov. 　Today's chess engines are significantly stronger than the best human players and have deeply influenced the development of chess theory. 　This article uses algebraic notation to describe chess moves.

Renaissance

The Renaissance (UK: /rɪˈneɪsəns/ rin-AY-sənss, US: /ˈrɛnəsɑːns/ (listen) REN-ə-sahnss) is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas and achievements of classical antiquity. 　It occurred after the Crisis of the Late Middle Ages and was associated with great social change. 　In addition to the standard periodization, proponents of a "long Renaissance" may put its beginning in the 14th century and its end in the 17th century. 　The traditional view focuses more on the early modern aspects of the Renaissance and argues that it was a break from the past, but many historians today focus more on its medieval aspects and argue that it was an extension of the Middle Ages. 　However, the beginnings of the period – the early Renaissance of the 15th century and the Italian Proto-Renaissance from around 1250 or 1300 – overlap considerably with the Late Middle Ages, conventionally dated to c. 　1250–1500, and the Middle Ages themselves were a long period filled with gradual changes, like the modern age; and as a transitional period between both, the Renaissance has close similarities to both, especially the late and early sub-periods of either. 　The intellectual basis of the Renaissance was its version of humanism, derived from the concept of Roman humanitas and the rediscovery of classical Greek philosophy, such as that of Protagoras, who said that "man is the measure of all things". 　This new thinking became manifest in art, architecture, politics, science, and literature. 　Early examples were the development of perspective in oil painting and the revived knowledge of how to make concrete. 　Although the invention of metal movable type sped the dissemination of ideas from the later 15th century, the changes of the Renaissance were not uniform across Europe: the first traces appear in Italy as early as the late 13th century, in particular with the writings of Dante and the paintings of Giotto. 　As a cultural movement, the Renaissance encompassed innovative flowering of Latin and vernacular literatures, beginning with the 14th-century resurgence of learning based on classical sources, which contemporaries credited to Petrarch; the development of linear perspective and other techniques of rendering a more natural reality in painting; and gradual but widespread educational reform. 　In politics, the Renaissance contributed to the development of the customs and conventions of diplomacy, and in science to an increased reliance on observation and inductive reasoning. 　Although the Renaissance saw revolutions in many intellectual and social scientific pursuits, as well as the introduction of modern banking and the field of accounting, it is perhaps best known for its artistic developments and the contributions of such polymaths as Leonardo da Vinci and Michelangelo, who inspired the term "Renaissance man". 　The Renaissance began in Florence, one of the many states of Italy. 　Various theories have been proposed to account for its origins and characteristics, focusing on a variety of factors including the social and civic peculiarities of Florence at the time: its political structure, the patronage of its dominant family, the Medici, and the migration of Greek scholars and their texts to Italy following the fall of Constantinople to the Ottoman Turks. 　Other major centers were Venice, Genoa, Milan, Rome during the Renaissance Papacy, and Naples. 　From Italy, the Renaissance spread throughout Europe in Flanders, France, Britain, Ireland, Spain, Portugal, Germany, Poland, Hungary (with Beatrice of Naples), and elsewhere. 　The Renaissance has a long and complex historiography, and in line with general scepticism of discrete periodizations, there has been much debate among historians reacting to the 19th-century glorification of the "Renaissance" and individual cultural heroes as "Renaissance men", questioning the usefulness of Renaissance as a term and as a historical delineation. 　Some observers have called into question whether the Renaissance was a cultural "advance" from the Middle Ages, instead seeing it as a period of pessimism and nostalgia for classical antiquity, while social and economic historians, especially of the longue durée, have instead focused on the continuity between the two eras, which are linked, as Panofsky observed, "by a thousand ties". 　The term rinascita ('rebirth') first appeared in Giorgio Vasari's Lives of the Artists (c. 1550), anglicized as the Renaissance in the 1830s. 　The word has also been extended to other historical and cultural movements, such as the Carolingian Renaissance (8th and 9th centuries), Ottonian Renaissance (10th and 11th century), and the Renaissance of the 12th century.

Sheep

Sheep or domestic sheep (Ovis aries) are domesticated, ruminant mammals typically kept as livestock. 　Although the term sheep can apply to other species in the genus Ovis, in everyday usage it almost always refers to domesticated sheep. 　Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. 　Numbering a little over one billion, domestic sheep are also the most numerous species of sheep. 　An adult female is referred to as a ewe (/juː/), an intact male as a ram, occasionally a tup, a castrated male as a wether, and a young sheep as a lamb. 　Sheep are most likely descended from the wild mouflon of Europe and Asia, with Iran being a geographic envelope of the domestication center. 　One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleeces, meat (lamb, hogget or mutton) and milk. 　A sheep's wool is the most widely used animal fiber, and is usually harvested by shearing. 　In Commonwealth countries, ovine meat is called lamb when from younger animals and mutton when from older ones; in the United States, meat from both older and younger animals is usually called lamb. 　Sheep continue to be important for wool and meat today, and are also occasionally raised for pelts, as dairy animals, or as model organisms for science. 　Sheep husbandry is practised throughout the majority of the inhabited world, and has been fundamental to many civilizations. 　In the modern era, Australia, New Zealand, the southern and central South American nations, and the British Isles are most closely associated with sheep production. 　There is a large lexicon of unique terms for sheep husbandry which vary considerably by region and dialect. 　Use of the word sheep began in Middle English as a derivation of the Old English word scēap; it is both the singular and plural name for the animal. 　A group of sheep is called a flock. 　Many other specific terms for the various life stages of sheep exist, generally related to lambing, shearing, and age. 　Being a key animal in the history of farming, sheep have a deeply entrenched place in human culture, and find representation in much modern language and symbology. 　As livestock, sheep are most often associated with pastoral, Arcadian imagery. 　Sheep figure in many mythologies—such as the Golden Fleece—and major religions, especially the Abrahamic traditions. 　In both ancient and modern religious ritual, sheep are used as sacrificial animals.

Egg

An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. 　Most arthropods such as insects, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. 　Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. 　Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. 　When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. 　Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. 　The largest recorded egg is from a whale shark and was 30 cm × 14 cm × 9 cm (11.8 in × 5.5 in × 3.5 in) in size. 　Whale shark eggs typically hatch within the mother. 　At 1.5 kg (3.3 lb) and up to 17.8 cm × 14 cm (7.0 in × 5.5 in), the ostrich egg is the largest egg of any living bird,: 130  though the extinct elephant bird and some non-avian dinosaurs laid larger eggs. 　The bee hummingbird produces the smallest known bird egg, which measures between 6.35–11.4 millimetres (0.250–0.449 in) long and weighs half of a gram (around 0.02 oz).　: 132  Some eggs laid by reptiles and most fish, amphibians, insects, and other invertebrates can be even smaller. 　Reproductive structures similar to the egg in other kingdoms are termed "spores," or in spermatophytes "seeds," or in gametophytes "egg cells".

Suspension (topology)

In topology, a branch of mathematics, the suspension of a topological space X is intuitively obtained by stretching X into a cylinder and then collapsing both end faces to points. 　One views X as "suspended" between these end points. 　The suspension of X is denoted by SX or susp(X).　: 76  There is a variation of the suspension for pointed space, which is called the reduced suspension and denoted by ΣX. 　The "usual" suspension SX is sometimes called the unreduced suspension, unbased suspension, or free suspension of X, to distinguish it from ΣX.

Derby

Derby (/ˈdɑːrbi/ (listen) DAR-bee) is a city and unitary authority area in Derbyshire, England. 　It lies on the banks of the River Derwent in the south of Derbyshire, which is in the East Midlands Region. 　It was traditionally the county town of Derbyshire. 　Derby gained city status in 1977. 　The last decade has seen the population increase by 5.1%, from around 248,800 in 2011 to 261,400 in 2021. 　Derby was settled by Romans, who established the town of Derventio, later captured by the Anglo-Saxons, and later still by the Vikings, who made their town of Djúra-bý one of the Five Boroughs of the Danelaw. 　Initially a market town, Derby grew rapidly in the industrial era. 　Home to Lombe's Mill, an early British factory, Derby has a claim to be one of the birthplaces of the Industrial Revolution.　[citation needed] It contains the southern part of the Derwent Valley Mills World Heritage Site. 　With the arrival of the railways in the 19th century, Derby became a centre of the British rail industry. 　Derby is a centre for advanced transport manufacturing, being home to the world's second largest aero-engine manufacturer: Rolls-Royce. 　Bombardier Transportation has a production facility at the Derby Litchurch Lane Works while Toyota Manufacturing UK's automobile headquarters is located southwest of the city at Burnaston.

Parade

A parade is a procession of people, usually organized along a street, often in costume, and often accompanied by marching bands, floats, or sometimes large balloons. 　Parades are held for a wide range of reasons, but are usually celebrations of some kind. 　In British English, the term "parade" is usually reserved for either military parades or other occasions where participants march in formation; for celebratory occasions, the word procession is more usual.　[citation needed] The term "parade" may also be used for multiple different subjects; for example, in the Canadian Armed Forces, "parade" is used both to describe the procession and in other informal connotations. 　Protest demonstrations can also take the form of a parade, but such cases are usually referred to as a march instead.

Mars

Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, larger only than Mercury. 　In the English language, Mars is named for the Roman god of war. 　Mars is a terrestrial planet with a thin atmosphere and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. 　Mars has surface features such as impact craters, valleys, dunes, and polar ice caps. 　Mars has two small, irregularly shaped moons, Phobos and Deimos. 　Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and highest-known mountain in the Solar System, and Valles Marineris, one of the largest canyons in the Solar System. 　The Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a large impact feature. 　Days and seasons on Mars are comparable to those of Earth, as the planets have a similar rotation period and tilt of the rotational axis relative to the ecliptic plane. 　Liquid water on the surface of Mars cannot exist due to low atmospheric pressure, which is less than 1% of the atmospheric pressure on Earth. 　Both of Mars's polar ice caps appear to be made largely of water. 　In the distant past, Mars was likely wetter, and thus possibly more suited for life. 　It is not known whether life has ever existed on Mars. 　Mars has been explored by several uncrewed spacecraft, beginning with Mariner 4 in 1965. 　NASA's Viking 1 lander transmitted the first images from the Martian surface in 1976. 　Two countries have successfully deployed rovers on Mars, the United States first doing so with Sojourner in 1997 and China with Zhurong in 2021. 　There are also planned future missions to Mars, such as a NASA-ESA Mars Sample Return set to happen in 2026, and the Rosalind Franklin rover mission, which was intended to launch in 2018 but was delayed to 2024 at the earliest, with a more likely launch date at 2028. 　Mars can be viewed from Earth with the naked eye, as can its reddish coloring. 　This appearance, due to the iron oxide prevalent on its surface, has led to Mars often being called the Red Planet. 　It is among the brightest objects in Earth's sky, with an apparent magnitude that reaches −2.94, comparable to that of Jupiter and surpassed only by Venus, the Moon and the Sun. 　Mars has been observed since ancient times. 　Over the millennia has been featured in culture and the arts in ways that have reflected humanity's growing knowledge of it.

Mars (mythology)

In ancient Roman religion and myth, Mars (Latin: Mārs, pronounced [maːrs]) was the god of war and also an agricultural guardian, a combination characteristic of early Rome. 　He was the son of Jupiter and Juno, and was pre-eminent among the Roman army's military gods. 　Most of his festivals were held in March, the month named for him (Latin Martius), and in October, which began the season for military campaigning and ended the season for farming. 　Under the influence of Greek culture, Mars was identified with the Greek god Ares, whose myths were reinterpreted in Roman literature and art under the name of Mars. 　The character and dignity of Mars differed in fundamental ways from that of his Greek counterpart, who is often treated with contempt and revulsion in Greek literature. 　Mars's altar in the Campus Martius, the area of Rome that took its name from him, was supposed to have been dedicated by Numa, the peace-loving semi-legendary second king of Rome; in Republican times it was a focus of electoral activities. 　Augustus shifted the focus of Mars' cult to within the pomerium (Rome's ritual boundary), and built a temple to Mars Ultor as a key religious feature of his new forum. 　Unlike Ares, who was viewed primarily as a destructive and destabilizing force, Mars represented military power as a way to secure peace, and was a father (pater) of the Roman people. 　In Rome's mythic genealogy and founding, Mars fathered Romulus and Remus through his rape of Rhea Silvia. 　His love affair with Venus symbolically reconciled two different traditions of Rome's founding; Venus was the divine mother of the hero Aeneas, celebrated as the Trojan refugee who "founded" Rome several generations before Romulus laid out the city walls.