337 résultats pour "must"

• Fire - chemistry.

  were usually natural caves. Eventually people learned to dip branches in pitch to form torches. They created crude lamps by filling a hollowed out piece of stone withmoss soaked in oil or tallow (a substance derived from animal fat). By cooking with fire, prehistoric people made the meat of the animals they killed more palatable and digestible. They learned to preserve meat by smoking it over a fire,vastly decreasing the danger of periodic starvation. Cooking also enabled them to add some for...

• Baseball.

  pitcher or argue a call with an umpire. Two or more coaches, positioned closer to the field, assist the manager by communicating with the players. For example,managers may decide what pitches should be thrown, when batters should swing at a pitch, and how runners should move around the bases. The manager relays thesedecisions through special hand signals that the coaches repeat to communicate to the players. Umpires are responsible for interpreting and enforcing the rules of play. They rule on...

• Geology.

  terminology. Today the geologic time scale is generally agreed upon and used by scientists around the world, dividing time into eons, eras, periods, and epochs. Everyfew years, the numerical time scale is refined based on new evidence, and geologists publish an update. Geologists use several methods to determine geologic time. These methods include physical stratigraphy, or the placement of events in the order of their occurrence,and biostratigraphy, which uses fossils to determine geologic time...

• Civil Rights and Civil Liberties.

  A Religious Freedom Although religious freedom has not generally been curtailed in the United States, Roman Catholics, Jews, and members of such unconventional Protestant groups as theOneida Community and the Church of Jesus Christ of Latter-day Saints have historically been discriminated against and sometimes have even been persecuted,although today overt discrimination has almost vanished. The federal Civil Rights Act of 1964, as well as many state and local laws, prohibits religious discrimi...

• Planetary Science - astronomy.

  III ORIGINS AND COMPOSITIONS OF PLANETS Astronomers believe that planetary systems are formed of elemental materials that were created in the interiors of giant stars. Some of this material comes from giantstars that shed material into space as they age. Most of the matter to form planets, however, comes from stars that explode as supernovas and spread debris enrichedwith the heavier chemical elements into space. According to the currently accepted views, the most likely first stage in the evo...

• The essence of Government is power; and power, lodged as it must be in human hands, will ever be liable to abuse ».

  d'abus, ces penseurs théorisèrent donc leur séparation. La séparation des pouvoirs est donc bien une recherche formelle d'équilibre entre les pouvoirs, au travers d'une constitution définissant leurs rôles et responsabilités ainsi que leur mode de relation. Il est fondamental de dire ici que l'idée même de séparation des pouvoirs revêt plusieurs dimensions : Une dimension que nous pourrions qualifier « d'institutionnelle » et une autre dimension plus « matérielle ». Dans sa dimension institution...

• Animals.

  All animals must breathe oxygen to stay alive. They must breathe out a waste gas called carbon dioxide. Some animals breathe through lungs. Lungs take oxygen out of air. Cattle, dogs, cats, whales, people,and other mammals breathe through lungs. Birds and reptiles also breathe air through lungs. Lungs cannot take air from water. Seals, whales, dolphins, and other mammals that live in waterbreathe through lungs. They can stay underwater a long time because they can hold their breath for along tim...

• SUJET NATIONAL, SESSION DE JUIN 1995 LANGUE VIVANTE 2 - SÉRIE L

  She looked at him. "Michael, you won't let him persuade you, will you?" "No, 1 won't." She turned and went off up the avenue, going towards the shops 30 on the high street. He unlocked the front door and went into the hall. A phone was ringing upstairs. He looked at his watch. lt was just after five. He began to run upstairs, pushing past a little red-haired man who was also on his way up. "Sorry ," he said. ''That's all right, guv. 2...

• Excerpt from Mansfield Park - anthology.

  arranged round the other. It was a fine arrangement for Henry Crawford, who was close to Fanny, and with his hands full of business, having two persons' cards tomanage as well as his own—for though it was impossible for Fanny not to feel herself mistress of the rules of the game in three minutes, he had yet to inspirit herplay, sharpen her avarice, and harden her heart, which, especially in any competition with William, was a work of some difficulty; and as for Lady Bertram, he mustcontinue in c...

• Arthurian Legend I INTRODUCTION King Arthur Legend and lore surround the life of Arthur, a medieval king of the Britons.

  Merlin and ArthurIn the tales of Arthurian legend, Merlin is an aged magician who helps bring King Arthur to power. Some authors alsodescribe Merlin as the young king’s tutor.Corbis Arthur is conceived when King Uther Pendragon falls in love with a married woman, Ygraine, and arranges for the magician Merlin to transform him into the likeness ofYgraine's husband. The husband, Gorlois, dies in battle, and Arthur's parents marry soon thereafter. Arthur Receiving ExcaliburAccording to legend, soon...

• Johnson Knocks Out Jeffries.

  Through the fight's first three rounds the boxers—picking, jabbing, and feigning—proceeded slowly. Even at this cautious pace Johnson scored several shatteringblows, smiling or laughing several times during the early rounds. By the fourth round Johnson was in control, and he continued to batter Jeffries for ten more rounds. In the 15th, Johnson knocked down Jeffries with a left. Theformer champion rose groggily to his feet only to be met by another left from Johnson to the jaw. This punch pr...

• Excerpt from Othello - anthology.

  MESSENGER. The Ottomites, reverend and gracious,Steering with due course toward the isle of Rhodes,Have there injointed with an after fleet. FIRST SENATOR. Ay, so I thought. How many, as you guess? MESSENGER. Of thirty sail; and now they do re-stemTheir backward course, bearing with frank appearanceTheir purposes toward Cyprus. Signor Montano,Your trusty and most valiant servitor,With his free duty recommends you thus,And prays you to believe him. DUKE. 'Tis certain then for Cyprus.Marcus Luccic...

• Excerpt from Dombey and Son - anthology.

  light. Rivers and seas were formed to float their ships; rainbows gave them promise of fair weather; winds blew for or against their enterprises; stars and planetscircled in their orbits, to preserve inviolate a system of which they were the centre. Common abbreviations took new meanings in his eyes, and had sole reference tothem. A.D. had no concern with anno Domini, but stood for anno Dombei—and Son. He had risen, as his father had before him, in the course of life and death, from Son to D...

• Excerpt from Barnaby Rudge - anthology.

  Mr. Dennis rolled lazily over upon his breast, and resting his chin upon his hand in imitation of the attitude in which Hugh lay, said, as he too looked towards thedoor: “ Ay, ay, you knew him, brother, you knew him. But who'd suppose to look at that chap now, that he could be the man he is! Isn't it a thousand cruel pities, brother,that instead of taking his nat'ral rest and qualifying himself for further exertions in this here honourable cause, he should be playing at soldiers like a boy?...

• Excerpt from Troilus and Cressida - anthology.

  Enter Pandarus and Cressida, veiled PANDARUS. Come, come, what need you blush? Shame's a baby. ( To Troilus ) Here she is now: swear the oaths now to her that you have sworn to me. ( To Cressida ) What, are you gone again? You must be watched ere you be made tame, must you? Come your ways, come your ways; an you draw backward, we'll put you i'th'fills. ( To Troilus ) Why do you not speak to her? ( To Cressida ) Come, draw this curtain, and let's see your picture. Alas the day, how loath you are...

• Smoking.

  causes about 20 times the number of deaths in the United States than all other addictive drugs combined. Smoking cessation methods are plentiful, and many books and products are available to help an individual stop smoking. Many smokers turn to group help because ofthe support and understanding provided by other former smokers or people trying to quit. Most successful group-help techniques involve a challenge and rewardsystem that also bolsters the self-discipline of the former smoker. A number...

• From "The Metamorphosis" - anthology.

  As all this was running through his mind at top speed without his being able to decide to leave his bed—the alarm clock had just struck a quarter to seven—therecame a cautious tap at the door behind the head of his bed. 'Gregor,' said a voice—it was his mother's—'it's a quarter to seven. Hadn't you a train to catch?' Thatgentle voice! Gregor had a shock as he heard his own voice answering hers, unmistakably his own voice, it was true, but with a persistent horrible twittering squeakbehind it lik...

• Connecticut Yankee - anthology.

  This missionary knight's name was La Cote Male Taile, and he said that this castle was the abode of Morgan le Fay, sister of King Arthur, and wife of King Uriens,monarch of a realm about as big as the District of Columbia—you could stand in the middle of it and throw bricks into the next kingdom. “Kings” and “Kingdoms”were as thick in Britain as they had been in little Palestine in Joshua's time, when people had to sleep with their knees pulled up because they couldn't stretch outwithout a passp...

• Schizophrenia.

  alcohol than other people. The use of alcohol and drugs often worsens the symptoms of schizophrenia, resulting in relapses and hospitalizations. IV CAUSES Schizophrenia appears to result not from a single cause, but from a variety of factors. Most scientists believe that schizophrenia is a biological disease caused by geneticfactors, an imbalance of chemicals in the brain, structural brain abnormalities, or abnormalities in the prenatal environment. In addition, stressful life events maycontri...

• Depression (psychology).

  IV CAUSES Some depressions seem to come out of the blue, even when things are going well. Others seem to have an obvious cause: a marital conflict, financial difficulty, or somepersonal failure. Yet many people with these problems do not become deeply depressed. Most psychologists believe depression results from an interaction betweenstressful life events and a person’s biological and psychological vulnerabilities. A Biological Factors Depression runs in families. By studying twins, researche...

• International Criminal Court.

  only exercise its jurisdiction when a national court is unwilling or unable to carry out the investigation or prosecution. For example, the ICC might intervene when agovernment’s judicial system has collapsed or is actively shielding a person from criminal responsibility. The court may hold accountable any person aged 18 or older at the time of the crime without regard to the individual’s official duties or functions. Therefore, heads ofstate, legislators, and other high-ranking government offic...

• Statistics I INTRODUCTION Statistics, branch of mathematics that deals with the collection, organization, and analysis of numerical data and with such problems as experiment design and decision making.

  Professional pollsters typically conduct their surveys among sample populations of 1,000 people. Statistical measurementsshow that reductions in the margin of error flatten out considerably after the sample size reaches 1,000.© Microsoft Corporation. All Rights Reserved. The raw materials of statistics are sets of numbers obtained from enumerations or measurements. In collecting statistical data, adequate precautions must be taken tosecure complete and accurate information. The first problem of...

• Electronics.

  electronic circuits. The resistors are made from carbon mixtures, metal films, or resistance wire and have two connecting wires attached. Variable resistors, with anadjustable sliding contact arm, are often used to control volume on radios and television sets. E Capacitors Capacitors consist of two metal plates that are separated by an insulating material ( see Capacitor). If a battery is connected to both plates, an electric charge will flow for a short time and accumulate on each plate. If th...

• Constitution of the United States.

  chief executive should have the power to veto legislation, should be elected by Congress or the people, should be eligible to run for reelection, and should command thearmed forces. Some delegates even hoped for a limited monarchy. Not until September 8, more than three months after the convention started, did the final shape ofthe presidency emerge: a single leader, elected to a four-year term and eligible for reelection, with authority to veto bills enacted by Congress. The president was alsog...

• Constitution of the United States - U.

  chief executive should have the power to veto legislation, should be elected by Congress or the people, should be eligible to run for reelection, and should command thearmed forces. Some delegates even hoped for a limited monarchy. Not until September 8, more than three months after the convention started, did the final shape ofthe presidency emerge: a single leader, elected to a four-year term and eligible for reelection, with authority to veto bills enacted by Congress. The president was alsog...

• The Merchant of Venice By William Shakespeare

  The Duke decides to spare Shylock's life, but he does give half of Shylock's money to Antonio, and he gives the rest of it to the state. Antonio says that he will not accept the money if Shylock will agree to become a Christian and if, in his will, he will agree to leave his money to his daughter, Jessica, and her new husband, Lorenzo. Shylock, broken and defeated, agrees to all these conditions and leaves the court. Overjoyed, Antonio and his friends offer to pay the young lawyer whatev...

• Lester Pearson.

  a vacant seat. The by-election followed a major Liberal victory in September, and as a Liberal Party candidate, Pearson won by a comfortable margin in Algoma East,Ontario. He was reelected to the House of Commons in elections between 1949 and 1965. He was immediately made secretary of state for external affairs in the cabinetof Prime Minister Louis St. Laurent. In this post, Pearson set a new standard of frank exchange and cooperation that brought him respect and esteem. However, manyCanadians w...

• Lester Pearson - Canadian History.

  a vacant seat. The by-election followed a major Liberal victory in September, and as a Liberal Party candidate, Pearson won by a comfortable margin in Algoma East,Ontario. He was reelected to the House of Commons in elections between 1949 and 1965. He was immediately made secretary of state for external affairs in the cabinetof Prime Minister Louis St. Laurent. In this post, Pearson set a new standard of frank exchange and cooperation that brought him respect and esteem. However, manyCanadians w...

• Andrew Johnson.

  As senator, Johnson continued to work for a homestead law, and he was disappointed when President James Buchanan vetoed the homestead act of 1860. On theslavery issue, Johnson still followed the orthodox Southern line, but with no great enthusiasm. He voted for the resolutions proposed in 1860 by Senator Jefferson Davisof Mississippi to implement the Dred Scott Decision of 1857, which stated that Congress could not prohibit slavery in the territories of the United States. C1 Presidential Electio...

• Andrew Johnson

  As senator, Johnson continued to work for a homestead law, and he was disappointed when President James Buchanan vetoed the homestead act of 1860. On theslavery issue, Johnson still followed the orthodox Southern line, but with no great enthusiasm. He voted for the resolutions proposed in 1860 by Senator Jefferson Davisof Mississippi to implement the Dred Scott Decision of 1857, which stated that Congress could not prohibit slavery in the territories of the United States. C1 Presidential Electio...

• Radioactivity I INTRODUCTION Marie Curie Working with her husband, Pierre Curie, French physicist Marie Curie discovered the radioactive elements polonium and radium in 1898.

  Rutherford when he allowed an alpha-emitting substance to decay near an evacuated thin-glass vessel. The alpha particles were able to penetrate the glass and werethen trapped in the vessel, and within a few days the presence of elemental helium was demonstrated by use of a spectroscope. Beta particles were subsequentlyshown to be electrons, and gamma rays to consist of electromagnetic radiation of the same nature as X rays but of considerably greater energy. A The Nuclear Hypothesis Rutherford...

• Cat. I INTRODUCTION Cat, small, mainly carnivorous animal, Felis silvestris catus, member of

  D Coat Colors The domestic cat's original coat color was probably grayish-brown with darker tabby stripes, a color that provides excellent camouflage in a variety of environments. Allother coat colors and patterns are the result of genetic mutations; for example, solid coat colors such as black and blue are the result of a gene that suppresses tabbystripes; an orange coat is the result of a gene that transforms black pigment to orange; and a solid white coat is the result of a gene that complet...

• Cat - biology.

  D Coat Colors The domestic cat's original coat color was probably grayish-brown with darker tabby stripes, a color that provides excellent camouflage in a variety of environments. Allother coat colors and patterns are the result of genetic mutations; for example, solid coat colors such as black and blue are the result of a gene that suppresses tabbystripes; an orange coat is the result of a gene that transforms black pigment to orange; and a solid white coat is the result of a gene that complet...

• Atom I INTRODUCTION Water Molecule A water molecule consists of an oxygen atom and two hydrogen atoms, which are attached at an angle of 105°.

  spontaneously break apart and change, or decay, into other atoms. Unlike electrons, which are fundamental particles, protons and neutrons are made up of other, smaller particles called quarks. Physicists know of six different quarks.Neutrons and protons are made up of up quarks and down quarks —two of the six different kinds of quarks. The fanciful names of quarks have nothing to do with their properties; the names are simply labels to distinguish one quark from another. Quarks are unique amo...

• Snake (reptile).

  in their heads that conduct sound. They are able to hear low-frequency sounds and to sense vibrations that travel through the ground or water. The majority of snakeshave good eyesight, especially for detecting moving objects, although most burrowing snakes can only distinguish between light and dark. Pit vipers, boas, and pythons have an unusual adaptation for detecting warm-blooded prey and predators. On the heads of these snakes are small pits lined with cellsthat are extremely sensitive to he...

• Inorganic Chemistry - chemistry.

  two electrically charged plates (positively charged top plate and negatively charged bottom plate). By measuring the difference in how fast these electron-laden oildrops fell when the metal plates were charged and uncharged, Millikan was able to calculate the total charge on each oil drop. Because each measurement was a wholenumber multiple of -1.60 × 10 -19 coulombs, Millikan concluded this was the charge carried by a single electron. Using Thomson’s electron charge-to-mass ratio, Millikan then...

• Beetle - biology.

  cut, or crush prey. Beetles that consume nectar from flowers use tubelike mouthparts to suck up nectar like a primitive straw. C Thorax The thorax, the body region behind the head, consists of three segments that provide attachments for the legs and wings. Each segment of the thorax carries a pair oflegs. The middle segment also bears the stiff wing sheaths called elytra, and the hind segment holds the membranous hind wings. D Legs Beetles have six jointed legs, each leg with five parts. The f...

• Star (astronomy) - astronomy.

  absorbing the missing colors of light. For example, the set of dark lines made by hydrogen includes a dark red line, the set of dark lines made by sodium includes a pairof dark yellow lines, and the set of dark lines made by iron includes lines of nearly every color. Each element in the gaseous outer layer of a star produces its ownparticular pattern of dark spectrum lines, depending on the temperature and pressure of the gas. Astronomers have observed spectrum lines, or spectra, for hundredsof...

• Culture.

  form of knowledge, such as scientific discoveries; objects, such as works of art; and traditions, such as the observance of holidays. C1 Ethnocentrism and Cultural Relativism Self-identity usually depends on culture to such a great extent that immersion in a very different culture—with which a person does not share common ways of life orbeliefs—can cause a feeling of confusion and disorientation. Anthropologists refer to this phenomenon as culture shock. In multicultural societies —societies s...

• Chemical Reaction - chemistry.

  Many groups of elements occur so often as ions that they are given names: nitrate, NO 3-; sulfate, SO 42-; and phosphate, PO 43-. The suffix -ate usually indicates the presence of oxygen. The positive ion, NH 4+, is called ammonium, as in NH 4Cl, ammonium chloride, or (NH 4)3PO4, ammonium phosphate. Rules for naming more complicated compounds exist, but many compounds have been given trivial names—for example, Na 2B4O7·10 H 2O, borax—or proprietary names—F(CF 2)nF, Teflon. These nonsystemat...

• Learning.

  B1 Acquisition The acquisition phase is the initial learning of the conditioned response—for example, the dog learning to salivate at the sound of the bell. Several factors can affect the speed of conditioning during the acquisition phase. The most important factors are the order and timing of the stimuli. Conditioning occurs most quickly when theconditioned stimulus (the bell) precedes the unconditioned stimulus (the food) by about half a second. Conditioning takes longer and the response is...

• From McCulloch v.

  our system shall exist. In discussing these questions, the conflicting powers of the General and State Governments must be brought into view, and the supremacy oftheir respective laws, when they are in opposition, must be settled. If any one proposition could command the universal assent of mankind, we might expect it would be this—that the Government of the Union, though limited in itspowers, is supreme within its sphere of action. This would seem to result necessarily from its nature. It is th...

• France - country.

  In both the Paris and Aquitaine basins, fertile soils derived from limestone and wind-deposited dust, called loess, have supported prosperous agriculture since ancienttimes. Other lowlands in France are scattered and relatively small. They include the Alsace Plain in the east, bordering Germany, the valley of the Rhône River in thesoutheast, and the Languedoc Plain along the Mediterranean coast. A2 Uplands France contains several regions of uplands, the worn down remains of ancient mountain sys...

• Colour and qualia

  Faced with the dilemmas posed by subjective colour for physicalist doctrine, some philosophers opt for eliminativism, the doctrine that subjective colour is not a genuine, or real, phenomenon after all. On this view the source of the puzzle is a conceptual confusion; a tendency to extend our judgments concerning objective colour, what appear to be intrinsic properties of the surfaces of physical objects, onto the properties of our mental states. Once we see that all that is happening ‘inside'...

• Banking.

  loans, and some commercial loans in addition to checking accounts and time deposits. Credit unions, SLAs, and savings banks help encourage thriftiness by paying interest to consumers who put their money in savings deposits. Consequently, creditunions, SLAs, and savings banks are often referred to as thrift institutions. Of the various types of banks in the United States, commercial banks account for the greatest single source of the financial industry’s assets. In 2000 the 8,528commercial banks...

• Prison.

  Furthermore, experts disagree about whether imprisoning criminals actually prevents further crime. Some critics charge that American prisons simply warehouseviolence—meaning that U.S. prison inmates are confined and incapacitated in large numbers, with little or no effort made to rehabilitate them. Critics have labeled theresult of this process turnstile justice, referring to the fact that most inmates are chronic and persistent offenders and return to prison following conviction for new crime...

• Comparative Anatomy.

  In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...

• Excerpt from Titus Andronicus - anthology.

  For that they will not intercept my tale.When I do weep they humbly at my feetReceive my tears and seem to weep with me,And were they but attirèd in grave weedsRome could afford no tribunes like to these.A stone is soft as wax, tribunes more hard than stones.A stone is silent and offendeth not,And tribunes with their tongues doom men to death.But wherefore stand'st thou with thy weapon drawn? LUCIUS. To rescue my two brothers from their death,For which attempt the Judges have pronouncedMy everla...

• Nanotechnology.

  ever-finer method of reducing material to the nanoscale size. Instead, nanostructures would be assembled atom by atom and molecule by molecule, from the atomiclevel up, just as occurs in nature. However, assembly at this scale has its own challenges. In school, children learn about some of these challenges when they study the random Brownian motion seen in particles suspended in liquids such as water. Theparticles themselves are not moving. Rather, the water molecules that surround the particles...

• Excerpt from Henry VI - anthology.

  SON. Ill blows the wind that profits nobody.This man whom hand to hand I slew in fightMay be possessèd with some store of crowns;And I, that haply take them from him now,May yet ere night yield both my life and themTo some man else, as this dead man doth me.—Who's this? O God! It is my father's face,Whom in this conflict I, unwares, have killed.O, heavy times, begetting such events!From London by the King was I pressed forth;My father, being the Earl of Warwick's man,Came on the part of York, pr...