单选题In 1965, the United States made important changes in its immigration laws, allowing many more immigrants to come and entirely eliminating the older laws' bias (偏见, 偏向) in favor of white European immigrants. As a result, the United States is now confronted with a new challenge—taking in large numbers of new immigrants who are nonwhite and non-European. About 90 percent are from Asia, Latin America, and the Caribbean. In addition to the large numbers of legal immigrants, for the first time the United States has significant numbers of illegal immigrants. Many worry about what the impact will be on the American society. Can the American economy expand enough to offer these new immigrants the same opportunities that others have had? What will be the effect on the traditional value system that has defined the United States for over 200 years? Many Americans see wonderful benefits for their country. Ben Wattenberg, a respected expert on American culture, believes that the "new immigration" will be of great help to the nation. According to Wattenberg, something very important is happening to the United States: It is becoming the first universal nation in history. Wattenberg believes that the United States will be the first nation where large numbers of people from every region on earth live in freedom under one government. This diversity, he says, will give the nation great influence and appeal to the rest of the world during the 21st century. Perhaps the United States will be described not as a "melting pot" or a "salad bowl" but as a "mosaic"—a picture made up of many tiny pieces of different colors. If one looks closely at the nation, the individuals of different colors and ethnic groups are still distinct and recognizable, but together they create a picture that is uniquely American. "E Pluribus Unum" —the motto of the United States from its beginning—means one composed of many. "Out of many, one. /

单选题When I try to understand ______ that prevents so many Americans from being as happy as one might expected, it seems to me that there are two causes. A. why it does B. what it does C. what it is D. why it is

单选题(2005)By next July, Tom_____here for five years.

单选题 Passage 5 The human being longs for a sense of being accomplished, of being able to do things, with his hand, with his mind, with his will. Each of us wants to feel he or she has the ability to do {{U}}(1) {{/U}} that is meaningful and that serves as a {{U}}(2) {{/U}} to our inherent abilities. It is easiest to see this {{U}}(3) {{/U}} the craftsman who lovingly shapes some cheap material into an object that may be either useful or beautiful or {{U}}(4) {{/U}}. You can see the carpenter or bricklayer stand aside and {{U}}(5) {{/U}} the product of his personal skill. But even {{U}}(6) {{/U}} there is no obvious end product that is {{U}}(7) {{/U}} attributable to one person's skill, researchers have found that employees find pride in accomplishment. Our own research in hospitals suggests that {{U}}(8) {{/U}} the housekeeping and laundry staffs take pride in the {{U}}(9) {{/U}} that in their own ways they are helping to cure sick people--and thus accomplishing a good deal. We're often misled by the complaints {{U}}(10) {{/U}} difficult work; deep {{U}}(11) {{/U}} most people regard their own capacity to conquer the tough job as the mark of their own unique {{U}}(12) {{/U}} Complaining is just {{U}}(13) {{/U}} of working. After all, how {{U}}(14) {{/U}} do you know who you are, except as you can demonstrate the ability of your {{U}}(15) {{/U}} to control you limbs and hands and words? You are, {{U}}(16) {{/U}} significant measure, what you can do. Some are deceived into thinking that people like to store up {{U}}(17) {{/U}}, to rest and save {{U}}(18) {{/U}} as much as possible. Just the {{U}}(19) {{/U}}. It is energy {{U}}(20) {{/U}} that is satisfying.

单选题Researchers have found that REM (rapid eye movement)sleep is important to human beings. This type of sleep generally occurs four or five times during one night of sleep lasting five minutes to forty minutes for each occurrence. The deeper a person's sleep becomes, the longer the periods of rapid eye movement. There are physical changes in the body to show that a person has changed from NREM (non-rapid eye movement)to REM sleep. Breathing becomes faster, the heart rate increases, and, as the name implies, the eyes begin to move quickly. Accompanying these physical changes in the body there is a very important characteristic of REM sleep. It is during REM sleep that a person dreams.

单选题(2003)My sewing machine is not working ______ .

单选题Even at the Vatican. not all sacred beliefs are absolute: Thou shalt not kill, but war can be just. Now, behind the quiet walls, a clash is shaping up involving two poles of near certainty: the church's long-held ban on condoms and its advocacy of human life. The issue is AIDS. Church officials recently confirmed that Pope Benedict XVI had requested a report on whether it might be acceptable for Catholics to use condoms in one narrow circumstance: to protect life inside a marriage when one partner is infected with H.I.V. or is sick with AIDS. Whatever the pope decides, church officials and other experts broadly agree that it is remarkable that so delicate an issue is being taken up. But they also agree that such an inquiry is logical, and particularly significant from this pope, who was Pope John Paul II’s strict enforcer of church doctrine. "In some ways, maybe he has got the greatest capacity to do it because there is no doubt about his orthodoxy," said the. Rev. Jon Fuller, a Jesuit physician who runs an AIDS clinic at the Boston Medical Center. The issue has surfaced repeatedly as one of the most complicated and delicate facing the church. For years, some influential cardinals and theologians have argued for a change for couples affected by AIDS in the name of protecting life, while others have fiercely attacked the possibility as demoting the church's long advocacy of abstinence and marital fidelity to fight the disease. The news broke just after Benedict celebrated his first anniversary as pope, a relatively quiet papal year. But he devoted his first encyclical to love, specifically between a man and a woman in marriage. Indeed, with regard to condoms, the only change apparently being considered is in the specific case of married couples. But any change would be unpopular with conservative Catholics, some of whom have expressed disappointment that Benedict has displayed a softer face now as defender of the faith than he did when he was still Cardinal Joseph Ratzinger, the papal adviser. "It's just hard to imagine that any pope—and this pope—would change the teaching," said Austin Ruse, president of the Culture of Life Foundation, a Catholic-oriented advocacy group in Washington that opposes abortion and contraception. It is too soon to know where the pope is heading. Far less contentious issues can take years to inch through the Vatican's nexus of belief and bureaucracy, prayer and politics, and Cardinal Javier Lozano Barragan, the pope's top aide on health care issues, and other officials declined requests for interviews.

单选题 Man has long wished to predict earthquakes. Recent findings indicate that reliable earthquake prediction is almost a reality. Before earthquakes occur, there frequently are changes in rock behavior that affect the velocities of other earthquake waves passing through the rocks. The former Soviet seismologists have used earthquake waves from other unrelated earthquakes to meas- ure the alterations in wave speed through rocks around a fault zone. For months to years before a particular earthquake, the former Soviet scientists observed that the strained rock in the fault zone was deformed in a way that slowed other earthquake wave that passed through the zone. Similar behavior has preceded earthquakes in California and New York. Changes in electrical resistance, water pressure l rock motion, and leakage of gas also can accompany the lowering of wave velocity. Fractures in the fault zone apparently open, which leads to a lowering of water pressure. When the fractures are filled by underground water, the continuing stress on the rocks is also exerted on the water in pores, which contributes to pressure within the rocks and ultimately causes further fault movement and earthquakes. These preliminary events have been observed and studied for many earthquakes. The larger the earthquake, apparently the longer the time during which the preliminary events take place. Careful observation and measurement of the early events will precede reliable forecasts. The preliminary events are most evident along normal and reverse fault systems, and strike-slip faults may not produce the same effect. Although earthquake forecasting is in its infancy, both American and the former Soviet scientists have been able to predict the occurrence of a few earthquakes. Understanding of the causes of earthquakes has opened several possibilities for their control. Underground nuclear explosions in Nevada have released strain energy stored in certain rocks. In some instances, the shock wave from the explosion has raised the strain on nearby fractures and faults enough to initiate fault movement. All of the resulting earthquakes have been small, but a large earthquake could conceivably be initiated. In the future, a situation may arise where it is desirable to deliberately initiate an earthquake near a heavily populated area because too large an amount of strain has accumulated on an active fault zone in the vicinity. If hazardous areas were left empty and if emergency services were standing at the ready, such action might be considered necessary to prevent a later much more damaging earthquake. However, the legal, environmental, and human problems would be large in- deed, perhaps too great for such action to be taken. Another possibility for earthquake control is much more exciting. Increasing water pressures can initiate faulting, as was unintentionally demonstrated by a deep well at the U. S. Army' s Rock Mountain Arsenal near Denver, Colorado, in the early 1960s. Disposal of nerve gas wastes in the well triggered movement along deeply buried inactive faults in the region. The liquid waste reduced frictional resistance along fault flat surface in the rocks surrounding the well, leading to movement along the faults. Earthquake activity in the area connected closely with the times of pumping of wastes into the disposal well, as was demonstrated convincingly by a Denver geologist, David Evans. Strain energy stored along the fault flat surface was apparently released by the fluid injection. Experiments by the U. S. Geological Survey in the Rangely oil field of northwestern Colorado have added to the experience gained from the study of the Denver earthquakes. The Survey geologists injected water in some of the Rangely wells, causing very small earthquakes. By withdrawing the water, the earthquakes were stopped. Although it is premature, many geologists believe we could eventually restrain earthquakes by injecting fluid into fault zones to permit slippage to take place gradually or in a series of small earthquakes. However, means must be found to control the areas affected and to be certain a major destructive quake is not initiated.

单选题Speaker A: Do you happen to know what' s on after the news?Speaker B:______A. There is no important news after that.B. I'm not interested in the programs.C. It's a documentary about animals.D. I hope to watch a movie after that.

单选题During her two-week stay in Beijing, Elizabeth never ______ a chrome(chance) to practice her Chinese.

单选题The doctor ______ that the patients disease was cancer. A) conducted B) confessed C) condemned D) concluded

单选题The two strangers talked as if they ______ friends for years.

单选题If we had taken the other road, we ______ earlier． A．might arrive B．had arrived C．might be arriving D．might have arrived

单选题California relies heavily on income from fruit crops, ______.

单选题Asia is ( ) among the seven continents.

单选题Many Europeans have a great puzzle in many things EXCEPT

单选题The sentence given to the criminal was much too ______;murder should carry the maximum penalty. A. negligent B. solitary C. lenient D. tedious