Prayer

Prayer is an invocation or act that seeks to activate a rapport with an object of worship through deliberate communication. 　In the narrow sense, the term refers to an act of supplication or intercession directed towards a deity or a deified ancestor. 　More generally, prayer can also have the purpose of thanksgiving or praise, and in comparative religion is closely associated with more abstract forms of meditation and with charms or spells. 　Prayer can take a variety of forms: it can be part of a set liturgy or ritual, and it can be performed alone or in groups. 　Prayer may take the form of a hymn, incantation, formal creedal statement, or a spontaneous utterance in the praying person. 　The act of prayer is attested in written sources as early as 5000 years ago. 　Today, most major religions involve prayer in one way or another; some ritualize the act, requiring a strict sequence of actions or placing a restriction on who is permitted to pray, while others teach that prayer may be practised spontaneously by anyone at any time. 　Scientific studies regarding the use of prayer have mostly concentrated on its effect on the healing of sick or injured people. 　The efficacy of prayer in faith healing has been evaluated in numerous studies, with contradictory results.

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). 　The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. 　Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. 　There are two types of pollination: self-pollination and cross-pollination. 　Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. 　Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. 　Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are positioned so that the pollen can land on the flower's stigma. 　This pollination does not require an investment from the plant to provide nectar and pollen as food for pollinators. 　Some flowers produce diaspores without fertilization (parthenocarpy). 　Flowers contain sporangia and are the site where gametophytes develop. 　Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen. 　After fertilization, the ovary of the flower develops into fruit containing seeds. 　In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to bring beauty to the environment, and also as objects of romance, ritual, esotericism, witchcraft, religion, holistic medicine, and as a source of food.

Hiding

Look up hiding in Wiktionary, the free dictionary. 　Hiding is obscuring something from view or rendering it inconspicuous. 　It may refer to: Hiding (programming), of inherited methods in object-oriented computer programming Hiding (TV series), a 2015 Australian television series Christoffer Hiding (born 1985), a Swedish singer Information hiding, in computer science, the hiding of design decisions in a computer program

Moth

Moths are a group of insects that includes all members of the order Lepidoptera that are not butterflies. 　They were previously classified as suborder Heterocera, but the group is paraphyletic with respect to butterflies (suborder Rhopalocera) and neither subrdinate taxa are used modern classifications. 　Moths making up the vast majority of the order. 　There are thought to be approximately 160,000 species of moth, many of which have yet to be described. 　Most species of moth are nocturnal, but there are also crepuscular and diurnal species.

Ion

An ion (/ˈaɪ.ɒn, -ən/) is an atom or molecule with a net electrical charge. 　The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. 　The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. 　A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. 　Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. 　Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. 　In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. 　Ions are also created by chemical interactions, such as the dissolution of a salt in liquids, or by other means, such as passing a direct current through a conducting solution, dissolving an anode via ionization.

Prediction

A prediction (Latin præ-, "before," and dicere, "to say"), or forecast, is a statement about a future event or data. 　They are often, but not always, based upon experience or knowledge. 　There is no universal agreement about the exact difference from "estimation"; different authors and disciplines ascribe different connotations. 　Future events are necessarily uncertain, so guaranteed accurate information about the future is impossible. 　Prediction can be useful to assist in making plans about possible developments.

Biography

A biography, or simply bio, is a detailed description of a person's life. 　It involves more than just the basic facts like education, work, relationships, and death; it portrays a person's experience of these life events. 　Unlike a profile or curriculum vitae (résumé), a biography presents a subject's life story, highlighting various aspects of their life, including intimate details of experience, and may include an analysis of the subject's personality. 　Biographical works are usually non-fiction, but fiction can also be used to portray a person's life. 　One in-depth form of biographical coverage is called legacy writing. 　Works in diverse media, from literature to film, form the genre known as biography. 　An authorized biography is written with the permission, cooperation, and at times, participation of a subject or a subject's heirs. 　An autobiography is written by the person themselves, sometimes with the assistance of a collaborator or ghostwriter.

Cleveland

Cleveland (/ˈkliːvlənd/ KLEEV-lənd), officially the City of Cleveland, is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. 　Located in the northeastern part of the state, it is situated along the southern shore of Lake Erie, across the U.S. maritime border with Canada, 252 miles (406 km) northeast of Cincinnati, 143 miles (230 km) northeast of Columbus, and approximately 60 miles (97 km) west of Pennsylvania. 　The largest city on Lake Erie and one of the major cities of the Great Lakes region, Cleveland ranks as the 54th-largest city in the U.S. with a 2020 population of 372,624. 　The city anchors both the Greater Cleveland metropolitan statistical area (MSA) and the larger Cleveland–Akron–Canton combined statistical area (CSA). 　The CSA is the most populous in Ohio and the 17th-largest in the country, with a population of 3.63 million in 2020, while the MSA ranks as 34th-largest at 2.09 million. 　Cleveland was founded in 1796 near the mouth of the Cuyahoga River by General Moses Cleaveland, after whom the city was named. 　Its location on both the river and the lake shore allowed it to grow into a major commercial and industrial center, attracting large numbers of immigrants and migrants. 　Cleveland is a port city, connected to the Atlantic Ocean via the Saint Lawrence Seaway. 　Its economy relies on diverse sectors that include higher education, manufacturing, financial services, healthcare, and biomedicals. 　The GDP for the Greater Cleveland MSA was $135 billion in 2019. 　Combined with the Akron MSA, the seven-county Cleveland–Akron metropolitan economy was $175 billion in 2019, the largest in Ohio, accounting for 25% of the state's GDP. 　Designated as a global city by the Globalization and World Cities Research Network, Cleveland is home to several major cultural institutions, including the Cleveland Museum of Art, the Cleveland Museum of Natural History, the Cleveland Orchestra, Playhouse Square, and the Rock and Roll Hall of Fame. 　Known as "The Forest City" among many other nicknames, Cleveland serves as the center of the Cleveland Metroparks nature reserve system. 　The city's major league professional sports teams include the Cleveland Browns, the Cleveland Cavaliers, and the Cleveland Guardians.

Monster

A monster is a type of fictional creature found in horror, fantasy, science fiction, folklore, mythology and religion. 　Monsters are very often depicted as dangerous and aggressive with a strange, grotesque appearance that causes terror and fear. 　Monsters usually resemble bizarre, deformed, otherworldly and/or mutated animals or entirely unique creatures of varying sizes, but may also take a human form, such as mutants, ghosts and spirits, zombies or cannibals, among other things. 　They may or may not have supernatural powers, but are usually capable of killing or causing some form of destruction, threatening the social or moral order of the human world in the process. 　Animal monsters are outside the moral order, but sometimes have their origin in some human violation of the moral law (e.g. in the Greek myth, Minos does not sacrifice to Poseidon the white bull which the god sent him, so as punishment Poseidon makes Minos' wife, Pasiphaë, fall in love with the bull. She copulates with the beast, and gives birth to the man with a bull's head, the Minotaur). 　Human monsters are those who by birth were never fully human (Medusa and her Gorgon sisters) or who through some supernatural or unnatural act lost their humanity (werewolves, Frankenstein's monster), and so who can no longer, or who never could, follow the moral law of human society. 　Monsters may also be depicted as misunderstood and friendly creatures who frighten individuals away without wanting to, or may be so large, strong and clumsy that they cause unintentional damage or death. 　Some monsters in fiction are depicted as mischievous and boisterous but not necessarily threatening (such as a sly goblin), while others may be docile but prone to becoming angry or hungry, thus needing to be tamed and taught to resist savage urges, or killed if they cannot be handled or controlled successfully. 　Monsters pre-date written history, and the academic study of the particular cultural notions expressed in a society's ideas of monsters is known as monstrophy. 　Monsters have appeared in literature and in feature-length films. 　Well-known monsters in fiction include Count Dracula, Frankenstein's monster, werewolves, vampires, demons, mummies, and zombies.

Identification (psychology)

Identification is a psychological process whereby the individual assimilates an aspect, property, or attribute of the other and is transformed wholly or partially by the model that other provides. 　It is by means of a series of identifications that the personality is constituted and specified. 　The roots of the concept can be found in Freud's writings. 　The three most prominent concepts of identification as described by Freud are: primary identification, narcissistic (secondary) identification and partial (secondary) identification. 　While "in the psychoanalytic literature there is agreement that the core meaning of identification is simple – to be like or to become like another", it has also been adjudged '"the most perplexing clinical/theoretical area" in psychoanalysis'.

Identification (biology)

Identification in biology is the process of assigning a pre-existing taxon name to an individual organism. 　Identification of organisms to individual scientific names (or codes) may be based on individualistic natural body features, experimentally created individual markers (e.g., color dot patterns), or natural individualistic molecular markers (similar to those used in maternity or paternity identification tests). 　Individual identification is used in ecology, wildlife management and conservation biology. 　The more common form of identification is the identification of organisms to common names (e. g., "lion") or scientific name (e. g., "Panthera leo"). 　By necessity this is based on inherited features ("characters") of the sexual organisms, the inheritance forming the basis of defining a class. 　The features may, e. 　g.　, be morphological, anatomical, physiological, behavioral, or molecular. 　The term "determination" may occasionally be used as a synonym for identification (e. g.), or as in "determination slips". 　Identification methods may be manual or computerized and may involve using identification keys, browsing through fields guide that contain (often illustrated) species accounts, comparing the organism with specimens from natural history collections, or taking images to be analyzed and compared against a pre-trained knowledge base with species information.

Payment

A payment is the voluntary tender of money or its equivalent or of things of value by one party (such as a person or company) to another in exchange for goods or services provided by them or to fulfill a legal obligation. 　The party making the payment is commonly called the payer, while the payee is the party receiving the payment. 　Payments can be effected in a number of ways, for example: the use of money, cheque, or debit, credit, or bank transfers, whether through mobile payment or otherwise the transfer of anything of value, such as stock, or using barter, or personal data, the exchange of one good or service for another. 　In general, payees are at liberty to determine what method of payment they will accept; though normally laws require the payer to accept the country's legal tender up to a prescribed limit. 　Payment is most commonly effected in the local currency of the payee unless the parties agree otherwise. 　Payment in another currency involves an additional foreign exchange transaction. 　The payee may compromise on a debt, i.e., accept part payment in full settlement of a debtor's obligation, or may offer a discount, E.G: For payment in cash, or for prompt payment, etc. 　On the other hand, the payee may impose a surcharge, for example, as a late payment fee, or for use of a certain credit card, etc. 　Payments are frequently preceded by an invoice or bill, which follows the supply of goods or services, but in some industries (such as travel and hotels) it is not uncommon for pre-payments to be required before the service is performed or provided. 　In some industries, a deposit may be required before services are performed, which acts as a part pre-payment or as security to the service provider. 　In some cases, progress payments are made in advance, and in some cases part payments are accepted, which do not extinguish the payer’s legal obligations. 　The acceptance of a payment by the payee extinguishes a debt or other obligation. 　A creditor cannot unreasonably refuse to accept a payment, but payment can be refused in some circumstances, for example, on a Sunday or outside banking hours. 　A payee is usually obligated to acknowledge payment by producing a receipt to the payer. 　A receipt may be an endorsement on an account as "paid in full". 　The giving of a guarantee or other security for a debt does not constitute a payment.

Determination

Determination is a positive emotional feeling that involves persevering towards a difficult goal in spite of obstacles. 　Determination occurs prior to goal attainment and serves to motivate behavior that will help achieve one's goal. 　Empirical research suggests that people consider determination to be an emotion; in other words, determination is not just a cognitive state, but rather an affective state. 　In the psychology literature, researchers have studied determination under other terms, including challenge and anticipatory enthusiasm; this may explain one reason for the relative lack of research on determination compared to other positive emotions. 　In the field of psychology, emotion research is heavily focused on negative emotions and the action tendencies that they encourage. 　However, recent work in positive psychology incorporates the study of determination as a positive emotion that pushes individuals toward action and results in important outcomes such as perseverance and determination take success.

Determination (biology)

In biology, determination is the process of matching a specimen of an organism to a known taxon, for example identifying a plant. 　The term is also used in cellular biology, where it means the act of the differentiation of stem cells becoming fixed. 　Various methods are used, for example single or multi-access identification keys.

Holiday

A holiday is a day or other period of time set aside for festivals or recreation. 　Public holidays are set by public authorities and vary by state or region. 　Religious holidays are set by religious organisations for their members and are often also observed as public holidays in religious majority countries. 　Some religious holidays such as Christmas have become or are becoming secularised by part or all of those who observe it. 　In addition to secularisation, many holidays have become commercialised due to the growth of industry. 　Holidays can be thematic, celebrating or commemorating particular groups, events or ideas, or non-thematic, days of rest which do not have any particular meaning. 　In Commonwealth English, the term can refer to any period of rest from work, such as vacations or school holidays. 　In American English, the holidays typically refers to the period from Thanksgiving to New Year's, which contains many important holidays in American culture.

Tension (geology)

In geology, the term "tension" refers to a stress which stretches rocks in two opposite directions. 　The rocks become longer in a lateral direction and thinner in a vertical direction. 　One important result of tensile stress is jointing in rocks. 　However, tensile stress is rare because most subsurface stress is compressive, due to the weight of the overburden.

Purple

Purple is any of a variety of colors with hue between red and blue. 　In the RGB color model used in computer and television screens, purples are produced by mixing red and blue light. 　In the RYB color model historically used by painters, purples are created with a combination of red and blue pigments. 　In the CMYK color model used in printing, purples are made by combining magenta pigment with either cyan pigment, black pigment, or both. 　Purple has long been associated with royalty, originally because Tyrian purple dye, made from the mucus secretion of a species of snail, was extremely expensive in antiquity. 　Purple was the color worn by Roman magistrates; it became the imperial color worn by the rulers of the Byzantine Empire and the Holy Roman Empire, and later by Roman Catholic bishops. 　Similarly in Japan, the color is traditionally associated with the emperor and aristocracy. 　According to contemporary surveys in Europe and the United States, purple is the color most often associated with rarity, royalty, magic, mystery, and piety. 　When combined with pink, it is associated with eroticism, femininity, and seduction.

Advertising

Advertising is the practice and techniques employed to bring attention to a product or service. 　Advertising aims to put a product or service in the spotlight in hopes of drawing it attention from consumers. 　It is typically used to promote a specific good or service, but there are wide range of uses, the most common being the commercial advertisement. 　Commercial advertisements often seek to generate increased consumption of their products or services through "branding", which associates a product name or image with certain qualities in the minds of consumers. 　On the other hand, ads that intend to elicit an immediate sale are known as direct-response advertising. 　Non-commercial entities that advertise more than consumer products or services include political parties, interest groups, religious organizations and governmental agencies. 　Non-profit organizations may use free modes of persuasion, such as a public service announcement. 　Advertising may also help to reassure employees or shareholders that a company is viable or successful. 　In the 19th century, soap businesses were among the first to employ large-scale advertising campaigns. 　Thomas J. Barratt was hired by Pears to be its brand manager—the first of its kind—and in addition to creating slogans and images he recruited West End stage actress and socialite Lillie Langtry to become the poster-girl for Pears, making her the first celebrity to endorse a commercial product. 　Modern advertising originated with the techniques introduced with tobacco advertising in the 1920s, most significantly with the campaigns of Edward Bernays, considered the founder of modern, "Madison Avenue" advertising. 　Worldwide spending on advertising in 2015 amounted to an estimated US$529.43 billion. 　Advertising's projected distribution for 2017 was 40.4% on TV, 33.3% on digital, 9% on newspapers, 6.9% on magazines, 5.8% on outdoor and 4.3% on radio. 　Internationally, the largest ("Big Five") advertising agency groups are Omnicom, WPP, Publicis, Interpublic, and Dentsu. 　In Latin, advertere means "to turn towards".

Taiwan

Coordinates: 24°N 121°E / 24°N 121°E / 24; 121 Taiwan, officially the Republic of China (ROC), is a country in East Asia. 　It is located at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northeast, and the Philippines to the south. 　The territories controlled by the ROC consist of 168 islands, with a combined area of 36,193 square kilometres (13,974 sq mi). 　The main island of Taiwan, also known as Formosa, has an area of 35,808 square kilometres (13,826 sq mi), with mountain ranges dominating the eastern two-thirds and plains in the western third, where its highly urbanised population is concentrated. 　The capital, Taipei, forms along with New Taipei City and Keelung the largest metropolitan area of Taiwan. 　Other major cities include Taoyuan, Taichung, Tainan, and Kaohsiung. 　With around 23.9 million inhabitants, Taiwan is among the most densely populated countries in the world. 　Taiwan has been settled for at least 25,000 years. 　Ancestors of Taiwanese indigenous peoples settled the island around 6,000 years ago. 　In the 17th century, large-scale Han Chinese (specifically the Hakkas and Hoklos) immigration to western Taiwan began under a Dutch colony and continued under the Kingdom of Tungning, the first predominantly Han Chinese state in Taiwanese history. 　The island was annexed in 1683 by the Qing dynasty of China and ceded to the Empire of Japan in 1895. 　The Republic of China, which had overthrown the Qing in 1911, took control of Taiwan following the surrender of Japan in 1945. 　Japan would renounce sovereignty over Taiwan in 1952. 　The immediate resumption of the Chinese Civil War resulted in the loss of the Chinese mainland to Communist forces who established the People's Republic of China, and the flight of the ROC central government to Taiwan in 1949. 　The effective jurisdiction of the ROC has since been limited to Taiwan, Penghu, and smaller islands. 　In the early 1960s, Taiwan entered a period of rapid economic growth and industrialisation called the "Taiwan Miracle". 　In the late 1980s and early 1990s, the ROC transitioned from a one-party state under martial law to a multi-party democracy, with democratically elected presidents since 1996. 　Taiwan's export-oriented industrial economy is the 21st-largest in the world by nominal GDP and 19th-largest by PPP measures, with a focus on steel, machinery, electronics and chemicals manufacturing. 　Taiwan is a developed country, ranking 20th on GDP per capita. 　It is ranked highly in terms of civil liberties, healthcare, and human development. 　The political status of Taiwan is contentious. 　The ROC no longer represents China as a member of the United Nations, after UN members voted in 1971 to recognize the PRC instead. 　The ROC maintained its claim of being the sole legitimate representative of China and its territory, although this has been downplayed since its democratization in the 1990s. 　Taiwan is claimed by the PRC, which refuses diplomatic relations with countries that recognise the ROC. 　Taiwan maintains official diplomatic relations with 13 out of 193 UN member states and the Holy See, though many others maintain unofficial diplomatic ties through representative offices and institutions that function as de facto embassies and consulates. 　International organisations in which the PRC participates either refuse to grant membership to Taiwan or allow it to participate only on a non-state basis under various names. 　Domestically, the major political contention is between parties favouring eventual Chinese unification and promoting a pan-Chinese identity, contrasted with those aspiring to formal international recognition and promoting a Taiwanese identity; into the 21st century, both sides have moderated their positions to broaden their appeal.

Consideration

Look up consideration in Wiktionary, the free dictionary. 　Consideration is a concept of English common law and is a necessity for simple contracts but not for special contracts (contracts by deed). 　The concept has been adopted by other common law jurisdictions. 　The court in Currie v Misa declared consideration to be a “Right, Interest, Profit, Benefit, or Forbearance, Detriment, Loss, Responsibility”. 　Thus, consideration is a promise of something of value given by a promissor in exchange for something of value given by a promisee; and typically the thing of value is goods, money, or an act. 　Forbearance to act, such as an adult promising to refrain from smoking, is enforceable only if one is thereby surrendering a legal right. 　Consideration may be thought of as the concept of value offered and accepted by people or organisations entering into contracts. 　Anything of value promised by one party to the other when making a contract can be treated as "consideration": for example, if A contracts to buy a car from B for $5,000, A's consideration is the promise of $5,000, and B's consideration is the promise of the car. 　Additionally, if A signs a contract with B such that A will paint B's house for $500, A's consideration is the service of painting B's house, and B's consideration is $500 paid to A. Further if A signs a contract with B such that A will not repaint his own house in any other colour than white, and B will pay A $500 per year to keep this deal up, there is also a consideration. 　Although A did not promise to affirmatively do anything, A did promise not to do something that he was allowed to do, and so A did pass consideration. 　A's consideration to B is the forbearance in painting his own house in a colour other than white, and B's consideration to A is $500 per year. 　Conversely, if A signs a contract to buy a car from B for $0, B's consideration is still the car, but A is giving no consideration, and so there is no valid contract. 　However, if B still gives the title to the car to A, then B cannot take the car back, since, while it may not be a valid contract, it is a valid gift. 　In common law it is a prerequisite that both parties offer consideration before a contract can be thought of as binding. 　The doctrine of consideration is irrelevant in many jurisdictions, although contemporary commercial litigant relations have held the relationship between a promise and a deed is a reflection of the nature of contractual considerations. 　If there is no element of consideration found, there is thus no contract formed. 　However, even if a court decides there is no contract, there might be a possible recovery under the doctrines of quantum meruit (sometimes referred to as a quasi-contract) or promissory estoppel.

Soundtrack

A soundtrack is recorded music accompanying and synchronised to the images of a motion picture, drama, book, television program, radio program, or video game; a commercially released soundtrack album of music as featured in the soundtrack of a film, video, or television presentation; or the physical area of a film that contains the synchronised recorded sound. 　In movie industry terminology usage, a sound track is an audio recording created or used in film production or post-production. 　Initially, the dialogue, sound effects, and music in a film each has its own separate track (dialogue track, sound effects track, and music track), and these are mixed together to make what is called the composite track, which is heard in the film. 　A dubbing track is often later created when films are dubbed into another language. 　This is also known as an M&E (music and effects) track. 　M&E tracks contain all sound elements minus dialogue, which is then supplied by the foreign distributor in the native language of its territory. 　Current dictionary entries for soundtrack document soundtrack as a noun, and as verb. 　An early attempt at popularizing the term “sound track” was printed in the magazine Photoplay in 1929. 　A 1992 technical dictionary entry in Academic Press Dictionary of Science and Technology does not distinguish between the form sound track and soundtrack. 　The contraction soundtrack came into public consciousness with the advent of so-called "soundtrack albums" in the late 1940s. 　First conceived by movie companies as a promotional gimmick for new films, these commercially available recordings were labeled and advertised as "music from the original motion picture soundtrack", or "music from and inspired by the motion picture." 　These phrases were soon shortened to just "original motion picture soundtrack." 　More accurately, such recordings are made from a film's music track, because they usually consist of isolated music from a film, not the composite (sound) track with dialogue and sound effects. 　The abbreviation OST is often used to describe the musical soundtrack on a recorded medium, such as CD, and it stands for original soundtrack; however, it is sometimes also used to differentiate the original music heard and recorded versus a rerecording or cover.

Debt

Debt is an obligation that requires one party, the debtor, to pay money or other agreed-upon value to another party, the creditor. 　Debt is a deferred payment, or series of payments, which differentiates it from an immediate purchase. 　The debt may be owed by sovereign state or country, local government, company, or an individual. 　Commercial debt is generally subject to contractual terms regarding the amount and timing of repayments of principal and interest. 　Loans, bonds, notes, and mortgages are all types of debt. 　In financial accounting, debt is a type of financial transaction, as distinct from equity. 　The term can also be used metaphorically to cover moral obligations and other interactions not based on a monetary value. 　For example, in Western cultures, a person who has been helped by a second person is sometimes said to owe a "debt of gratitude" to the second person.

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. 　It can also be defined as the longest chord of the circle. 　Both definitions are also valid for the diameter of a sphere. 　In more modern usage, the length d {\displaystyle d} of a diameter is also called the diameter. 　In this sense one speaks of the diameter rather than a diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r . 　{\displaystyle r.　} d = 2 r or equivalently r = d 2 . 　{\displaystyle d=2r\qquad {\text{or equivalently}}\qquad r={\frac {d}{2}}.　} For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the width is often defined to be the smallest such distance. 　Both quantities can be calculated efficiently using rotating calipers. 　For a curve of constant width such as the Reuleaux triangle, the width and diameter are the same because all such pairs of parallel tangent lines have the same distance. 　For an ellipse, the standard terminology is different. 　A diameter of an ellipse is any chord passing through the centre of the ellipse. 　For example, conjugate diameters have the property that a tangent line to the ellipse at the endpoint of one diameter is parallel to the conjugate diameter. 　The longest diameter is called the major axis. 　The word "diameter" is derived from Ancient Greek: διάμετρος (diametros), "diameter of a circle", from διά (dia), "across, through" and μέτρον (metron), "measure". 　It is often abbreviated DIA , dia , d , {\displaystyle {\text{DIA}},{\text{dia}},d,} or ∅ . 　{\displaystyle \varnothing .　}

Sculpture

Sculpture is the branch of the visual arts that operates in three dimensions. 　Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. 　It is one of the plastic arts. 　Durable sculptural processes originally used carving (the removal of material) and modelling (the addition of material, as clay), in stone, metal, ceramics, wood and other materials but, since Modernism, there has been an almost complete freedom of materials and process. 　A wide variety of materials may be worked by removal such as carving, assembled by welding or modelling, or moulded or cast. 　Sculpture in stone survives far better than works of art in perishable materials, and often represents the majority of the surviving works (other than pottery) from ancient cultures, though conversely traditions of sculpture in wood may have vanished almost entirely. 　However, most ancient sculpture was brightly painted, and this has been lost. 　Sculpture has been central in religious devotion in many cultures, and until recent centuries large sculptures, too expensive for private individuals to create, were usually an expression of religion or politics. 　Those cultures whose sculptures have survived in quantities include the cultures of the ancient Mediterranean, India and China, as well as many in Central and South America and Africa. 　The Western tradition of sculpture began in ancient Greece, and Greece is widely seen as producing great masterpieces in the classical period. 　During the Middle Ages, Gothic sculpture represented the agonies and passions of the Christian faith. 　The revival of classical models in the Renaissance produced famous sculptures such as Michelangelo's statue of David. 　Modernist sculpture moved away from traditional processes and the emphasis on the depiction of the human body, with the making of constructed sculpture, and the presentation of found objects as finished art works.