The record of the past half century has established, I think, the two general principles a

demand payment all at the same time. If depositors should come to fear that a bank is not sound, that it cannot pay off all its depositors, then that fear might cause all the depositors to appear on the same day. If they did. the bank could not pay all accounts. However, if they did not all appear at once, then there would always be funds to pay those who wanted their money when they wanted it. Mrs. Elsie Vaught has told us of a terrifying bank run that she experienced. One day in December of 1928, several banks failed to open in a city where Mrs. Vaught lived. The other banks anticipated a run the next day, and so the officers of the bank in which Mrs. Vaught worked as a teller had enough funds on hand to pay off as many depositors as might apply. The officers simply instructed the tellers to pay on demand. Next morning a crowd gathered in the bank and on the sidewalk outside. The length of the line convinced many that the bank could not possibly pay off everyone. People began to push and then to fight for places near tellers windows. Clothing was torn and limbs broken, but the jam continued for hours. The power of the panic atmosphere is evident in the fact that two tellers, though they knew that the bank was sound and could pay out all depositors, nevertheless withdrew the funds in their own accounts. Mrs. Vaught says that she had difficulty restraining herself from doing the same.

A bank run occurs when______.

A．a bank is closed for one or more days

B．too many depositors attempt to draw out their money at one time

C．there is not enough money to pay all of its depositors at one time

D．employees of a bank take their own funds out of the bank

ly double. As an example of this type of growth rate, take one penny and double it every day for one month. After the first week you would have only 64 cents, but after the fourth week you would have over million dollars. This helps explain why the population has come on "all of a sudden". It took from the beginning of human life to the year 1830 for the population of the earth to reach one billion. That represents a time span of at least two million years. Then it took from 1830 to 1930 for world population to reach 2 billion. The next billion was added by 1960, only thirty years, and in 1979 world population reached 4 billion, which is another billion people in only fifteen years. World population is increasing at a rate of 9 000 per hour, 220 000 per day, 80 million per year. This is not only due to high birth rates, but to lower death rates as well. The number of births has not declined at the same rate as the number of deaths. Some countries, such as Colombia, Thailand, Morocco, Costa Rica, and the Philippines, are doubling their populations about every twenty-one years, with a growth rate of 3. 3 percent a year or more. The United States is doubling its population about every eighty-seven years, with a rate of 0. 8 percent per year. Every time a population doubles, the country involved needs twice as much of everything, including hospitals, schools, resources, food and medicines to care for its people, it is easy to see that this is very difficult to achieve for the more rapidly growing countries.

This passage chiefly discusses______.

A．the growth of world population in recent years

B．one type of the exponential rate

C．the population problem of the more rapidly growing countries

D．the possible ways of dealing with the rapid population growth

hierarchies; there are both state and federal courts. Each state has its own system of courts,composed of civil and criminal trial courts, sometimes intermediate courts of appeal, and a state supreme court. The federal court system consists of a series of trial courts (called district courts) serving relatively small geographic regions (there is at least one for every state), a tier (系列, 等级) of circuit (巡回) courts of appeal that hear appeals from many district courts in a particular geographic region, and the Supreme Court of the United States. The two court systems are to some extent overlapping, in that certain kinds of disputes (such as a claim that a state law is in violation of the Constitution) may be initiated in either system. They are also to some extent hierarchical, for the federal system stands above the state system in that litigants (诉讼当事人) (persons engaged in lawsuits) who lose their cases in the state supreme court may appeal their cases to the Supreme Court of the United States. Thus, the typical court case begins in a trial court—a court of general jurisdiction (司法) in the state or federal system. Most cases go no further than the trial court: for example, the criminal defendant is convicted (by a trial or a guilty plea) and sentenced by the court and the case ends; the personal injury suit results in a judgment by a trial court [or an out-of-court settlement by the parties while the court suit is pending (悬而未决的)] and the parties leave the court system. But sometimes the losing party at the trial court care enough about the course that the matter does not end there. In these cases, the "loser" at the trial court may appeal to the next higher court.

What does the passage mainly discuss?

A．Civil and criminal courts.

B．Typical court cases.

C．The court system in US.

D．The appeal court process.

th and 11th centuries. As a wife, the woman was protected by the setting up of a dowry (嫁妆) or decimum. Admittedly, the purpose of this was to protect her against the risk of desertion (离弃、 抛弃), but in reality its function in the social and family life of the time was much more important. The decimum was the wifes right to receive a tenth of all her husbands property. The wife had the right to withhold consent in all transactions the husband would make. And more than just a right; the documents show that she enjoyed a real power of decision, equal to that of her husband. In no case do the documents indicate any degree of difference in the legal status of husband and wife. The wife shared in the management of her husbands personal property but the opposite was not always true. Women seemed perfectly prepared to defend their own inheritance against husbands who tried to exceed their rights, and on occasion they showed a fine fighting spirit. A case in point is that of Maria Vivas, a Catalan woman of Barcelona. Having agreed with her husband Miro to sell a field she had inherited, for the needs of the household, she insisted on compensation. None being offered, she succeeded in dragging her husband to the scribe (文书,抄写员) to have a contract duly (适时地,正式地) drawn up assigning her a piece of land from Miros personal inheritance. The unfortunate husband was obliged to agree, as the contract says, "for the sake of peace. " Either through dowry or through being hot-tempered, the Catalan wife knew how to win herself, within the context of the family, a powerful economic position.

A decimum was______.

A．the wife"s right to receive one-tenth of her husband"s property

B．a written contract

C．a gift of money to the new husband

D．the wife"s inheritance from her father

animals cannot. Even the cleverest animals cannot do things which to us seem very simple and which small children, as soon as they learn to talk, would be able to do. A German scientist, who made experiments for many years with big apes, found that his apes could use sticks as tools to pull down bananas which they could not reach. But they only used the stick to get a banana when both the stick and the banana were in view at the same time. If the banana was in front of them and the stick was behind them, they could not use the stick. They could not bear the banana in mind long enough to look around and pick up the stick and then use it. The reason for this is clear. We have words for banana and stick which help us to think about these things when they are not in sight. Even a small child knowing the words "banana" and "stick" has an idea of their relationship and is able to think of "stick" together with "banana" and to remember this long enough to pick the stick from behind and use it on the banana. Unable to speak, animals cannot keep their knowledge of things for long. That is why they often interrupt one line of action to something else and later forget it completely. Human beings, on the other hand, use language and are able to go after one thing continuously and do it with a definite aim.

Human beings and animals act very differently because______.

A．human beings know how to use a stick while animals don"t know

B．human beings can think while animals can"t

C．human beings have a good memory while animals haven"t

D．human beings can speak while animals can"t

of a year or more, a solemn public duty follows hot on the heels of the excitement of their twenty-first birthday. They must register as voters. Having done so, they cannot, as can some American or English adults if they so wish, then forget all about it—voting is compulsory in Australia. Failure to vote without a "true, valid, and sufficient reason" can result in a fine for an Australian citizen. Australians must vote frequently, too, for in proportion to its size, Australia is a much-governed country. For its ten million persons it has seven parliaments—one for each of six states and one commonwealth, or federal, parliament with representatives from all states. Every adult, unless he lives in one of the two territories that do not have state status, must do his share in electing both state and federal representatives. Whats more, with only one exception, these parliaments have two houses each and comprise among them 701 members. This may seem a great many politicians to govern Australias relatively small population of ten million especially when one considers that 630 members of Britains House of Commons govern forty million people. But just as government in the United States and England developed gradually as the result of events in those two countries, so the Australian system has developed in response to the needs of the nation.

What follows an Australians twenty-first birthday?

A．Termination of any prison sentence.

B．Public solemnity.

C．Voting in a national election.

D．Registration to vote.

wonder drug that is proving to be effective in treating a variety of ailments, including virus infections, bacteria infections, and tumors. To date, the new drug has provoked no negative reaction of sufficient significance to discourage its use. But in spite of its success, last year only one gram was produced in the entire world. The reason for the scarcity lies in the structure of interferon. A species specific protein, the interferon produced from one animal species cannot be used in treating another animal species. In other words, to treat human beings, only interferon produced by human beings may be used. The drug is produced by infecting white blood cells with a virus. Fortunately, it is so potent that the amount given each patient per injection is very small. Unlike antibiotics, interferon does not attack germs directly. Instead, it makes unaffected cells resistant to infection, and prevents the multiplication of viruses within cells. As you might conclude, one of the most dramatic uses of interferon has been in the treatment of cancer. Dr. Hans Strander, research physician at Swedens famous Karohnska Institute, has treated more than one hundred cancer patients with the new drug. Among a group of selected patients who had undergone surgical procedures for advanced cancer, half were given conventional treatments and the other half were given interferon. The survival rate over a three-year period was 70 percent among those who were treated with interferon as compared with only 10 to 30 percent among those who had received the conventional treatments. In the United States, a large-scale project supported by the American Cancer Society is now underway. If the experiment is successful, interferon could become one of the greatest medical discoveries of our time.

In what does interferon differ from antibiotics?

A．Interferon has serious side effects, whereas antibiotics do not.

B．Interferon is available in large supply, whereas antibiotics are not.

C．Antibiotics are very potent, while interferon is not.

D．Antibiotics kill germs by attacking them directly, while interferon does not.

reat writers. Before considering this question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities (统一体，实体) directed against one another, is distinguished from competition, defined as opposition among social entities independently striving for something which is in inadequate supply. Competitors may not be aware of one another, while the parties to a conflict are. Conflict and competition are both categories of opposition, which has been defined as a process by which social entities function in the disservice of one another. Opposition is thus contrasted with cooperation, the process by which social entities function in the service of one another. These definitions are necessary because it is important to emphasize that competition between individuals of groups is inevitable in a world of limited resources, but conflict is not. Conflict, nevertheless, is very likely to occur, and is probably an essential and desirable element of human societies. Many authors have argued for the inevitability of war from the premise that in the struggle for existence among animal species, only the fittest survive. In general, however, this struggle in nature is competition, not conflict. Social animals, such as monkeys and cattle, fight to win or maintain leadership of the group. The struggle for existence occurs not in such fights, but in the competition for limited feeding areas and for the occupancy (占有) of areas free from meat-eating animals. Those who fail in this competition starve to death or become victims to other species. This struggle for existence does not resemble human war, but rather the competition of individuals for jobs, markets, and materials. The essence of the struggle is the competition for the necessities of life that are insufficient to satisfy all. Among nations there is competition in developing resources, trades, skills, and a satisfactory way of life. The successful nations grow and prosper (繁荣); the unsuccessful decline. While it is true that this competition may induce efforts to expand territory at the expense of others, and this leads to conflict, it cannot be said that war-like conflict among nations is inevitable, although competitions are.

In the first paragraph, the author gives the definitions of some terms in order to______.

A．argue for the similarities between animal societies and human societies

B．smooth out the conflicts in human societies

C．distinguish between two kinds of opposition

D．summarize the characteristic features of opposition and cooperation

here were great migrations of Rocky Mountain locusts (Melanoplus spretus). Great migrating hordes of these insects once darkened the skies on the plains east of the Rockies where crops were often destroyed; the worst years were those from 1874 to 1877. One of these migrating swarms was estimated to contain 124 billion locusts. During another migration in Nebraska it was estimated that the swarm of locusts averaged half a mile high and was 100 miles wide and 300 miles long. Usually, these swarms take off from the ground against the wind, but, once airborne, they turn and fly with it. Warm convection (对流) currents help to lift them, often to great heights. During the great locust plagues the situation in Nebraska became so serious that the original state constitution had to be rewritten to take care of the economic problems. The new document was known as "The Grasshopper Constitution". It is now believed that these locusts were a migratory form. or phase of the lesser migratory locust, which is still common there. In this respect, the North American migratory locusts resemble their African relatives. In both regions the migratory forms arise as a result of crowding and climatic factors. Migratory forms are apparently natural adaptations which bring about dispersal when locust populations become too crowded. Fortunately for our farmers, the migratory form—the so called spretus species—no longer seems to occur regularly, although there was a serious outbreak as late as 1938 in midwestern United States and Canada. Actually, there is no reason why the destructive migratory form. might not again appear if circumstances should become favorable.

Which of the following is the best title for the passage?

A．The Life Cycle of Locusts.

B．Migratory Locusts in the United States.

C．Locust Plagues in Nebraska.

D．The Reproductive Capability of the Locust.

as a severe shock to the patient and his family. Despite modern advances most people still have an irrational fear of hospitals and anaesthetic. Patients do not often believe they really need surgery—cutting into a part of the body as opposed to treatment with drugs. In the early years of this century there was little specialization in surgery. A good surgeon was capable of performing almost every operation that had been devised up to that time. Today the situation is different. Operations are now being carried out that were not even dreamed of fifty years ago. The heart can be safely opened and its valves repaired. Clogged blood vessels can be cleaned out, and broken ones mended or replaced A lung, the whole stomach, or even part of the brain can be removed and still permit the patient to live a comfortable and satisfactory life. However, not every surgeon wants to, or is qualified to carry out every type of modern operation. The scope of surgery has increased remarkably in this century. Its safety has increased too. Deaths from most operations are about 20% of what they were in 1910 and surgery has been extended in many directions, for example, to certain types of birth defects in newborn babies, and, at the other end of the scale, to life-saving operations for the octogenarian (80岁至89岁之间的人). Many developments in modern surgery are almost incredible. They include the replacement of damaged blood vessels with simulated ones made of plastic; the replacement of heart valves with plastic substitutes; the transplanting of tissues such as the lens of the eye; the invention of the artificial kidney to clean the blood of poisons at regular intervals and the development of heart and lung machines to keep patients alive during very long operations. All these things open a hopeful vista for the future of surgery.

Most people are afraid of being operated on______.

A．in spite of improvements in modern surgery

B．because they think modern drugs are dangerous

C．because they do not believe they need anaesthetic

D．unless it is an emergency operation