单选题You must ______ the facts and should not run away from the truth.A. lookB. sightC. frontD. face

单选题For more than thirty years after astronauts first set foot on the Moon, scientists have been unable to unravel the mystery of where the Earth's only satellite came from. But now there is direct evidence that the Moon was born after a giant collision between the young Earth and another planet. Previous studies of rocks from the Earth and the Moon have been unable to distinguish between the two, suggesting that they formed from the same material. But this still left room for a number of theories explaining how—for example, that the Moon and Earth formed from the same material at the same time. It was even suggested that the early Earth spun so fast it formed a bulge that eventually broke off to form the Moon. Franck Poitrasson, and his colleagues at the Swiss Federal Institute of Technology have compared Moon rocks with rocks from Earth and discovered a surprising difference. They analysed the weight of the elements present in the rock using a highly accurate form of mass spectroscopy(光谱研究) that involves vaporising a sample by passing it through an argon (氩) flame. Although they appeared very similar in most respects, the Moon rocks had a higher ratio of iron-57 to iron-54 isotopes(同位素)than the Earth rocks. "The only way we could explain this difference is that the Moon and the Earth were partly vaporised during their formation," says Poitrasson. Only the popular "giant planetary impact" theory could generate the temperatures of more than 1700℃ needed to vaporise iron. In this scenario, a Mars-sized planet known as Theia crashed into Earth 50 million years after the birth of the Solar System. This catastrophic collision would have released 100 million times more energy than the impact believed to have wiped out the dinosaurs—enough to melt and vaporise a large portion of the Earth and completely destroy Theia. The debris from the collision would have been thrown into orbit around the Earth and eventually coalesced to form the Moon. When iron is vaporised, the lighter isotopes burn off first. And since the ejected debris that became the Moon would have been more thoroughly vaporised, it would have lost a greater proportion of its lighter iron isotopes than Earth did. This would explain the different ratios that Poitrasson has found.

单选题My golf is not very good just now. I've been busy and I'm out of______.

单选题I would appreciate it ______ you call back this afternoon for the doctor's appointment．A．untilB．ifC．whenD．that

单选题Speaker A: Looks like you've got a lot of reading to do. Speaker B: ______ A. Do you like reading in your spare time? B. Yes, if you like, you may borrow some of my books. C. And that's just for my philosophy class. D. That's right, because reading is a good way to enlarge your vocabulary.

单选题In the first sentence, "to become commercially available" means ______.

单选题Speaker A: I'd like to check in, please. Speaker B: ______ A. Certainly. Do you have a reservation? B. Sorry, I don't see what you mean. C. Sure, I can help you with the checking. D. Thank you, we provide first class service here.

单选题 A. fort{{U}}u{{/U}}ne B. p{{U}}u{{/U}}blic C. R{{U}}u{{/U}}ssia D. s{{U}}u{{/U}}ffer

单选题{{B}}Passage Two{{/B}} Between the invention of agriculture and the commercial revolution that marked the end of the Middle Ages, wealth and technology developed slowly indeed. Medieval historians tell of the centuries it took for key inventions like the watermill or the heavy plow to diffuse across the landscape. During this period, increases in technology led to increases in the population, with little if any appearing as an improvement in the median standard of living. Even the first century of the industrial revolution produced more "improvements" than "revolutions" in standards of living. With the railroad and the spinning and weaving of textiles as important exceptions, most innovations of that period were innovations in how goods were produced and transported, and in new kinds of capital, but not in consumer goods. Standards of living improved but styles of life remained much the same. The eighteenth and nineteenth centuries saw a faster and different kind of change. For the first time, technological capability outran population growth and natural resource scarcity. By the last quarter of the nineteenth century, the typical inhabitant of the leading economies—a British, a Belgian, an American, or an Australian had perhaps three times the standard of living of someone in a pre-industrial economy. Still, so slow was the pace of change that people, or at least aristocratic intellectuals, could think of their predecessors of some two thousand years before as effectively their contemporaries. Marcus Tullius Cicero, a Roman aristocrat and politician, might have felt more or less at home in the company of Thomas Jefferson. The plows were better in Jefferson's time. Sailing ships were much improved. However, these might have been insufficient to create a sense of a qualitative change in the order of life for the elite. Moreover, being a slave of Jefferson was probably a lot like being a slave of Cicero. So slow was the pace of change that intellectuals in the early nineteenth century debated whether the industrial revolution was worthwhile, whether it was an improvement or a degeneration in the standard of living. Opinions were genuinely divided, with as optimistic a liberal as John Stuart Mill coming down on the "pessimist" side as late as the end of the 1840s. In the twentieth century, however, standards of living exploded. In the twentieth century, the magnitude of the growth in material wealth has been so great as to make it nearly impossible to measure. Consider a sample of consumer goods available through Montgomery Ward in 1895 when a one-speed bicycle cost $65. Since then, the price of a bicycle measured in "nominal" dollars has more than doubled (as a result of inflation). Today, the bicycle is much less expensive in terms of the measure that truly counts, its "real" price: the work and sweat needed to earn its east. In 1895, it took perhaps 260 hours' worth of the average American worker's production to amass enough money to buy a one-speed bicycle. Today an average American worker can buy one—and of higher quality—for less than 8 hours worth of production. On the bicycle standard (measuring wealth by counting up how many bicycles the labor can buy) the average American worker today is 36 times richer than his or her counterpart was in 1895. Other commodities would tell a different story. An office chair has become 12.5 times cheaper in terms of the time it takes the average worker to produce enough to pay for it. A Steinway piano or an accordion is only twice as cheap. A silver teaspoon is 25 percent more expensive. Thus the answer to the question "How much wealthier are we today than our counterparts of a century ago?" depends on which commodities you view as important. For many personal services—having a butler to answer the door and polish your silver spoons—you would find little difference in average wealth between 1895 and 1990: an hour of a butler's time costs about the same then as now. For mass-produced manufactured goods—like bicycles—we are wealthier by as much as 36 times.

单选题In today's modern society alcohol addiction and alcohol______has become one of the most complex life-threatening issues.

单选题According to the research of NCAR, if the concentrations were held steady at 2000 levels,

单选题In the writer's opinion, humans are the sharks' worst enemies because ______.

单选题In the following, which subject is the safest one to start a conversation?

单选题 Directions: There are 6 passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.{{B}}Passage One{{/B}} The table before which we sit may be, as the scientist maintains, composed of dancing atoms, but it does not reveal itself to us as anything of the kind, and it is not with dancing atoms but a solid and motionless object that we live. So remote is this "real" table--and most of the other "realities" with which science deals--that it cannot be discussed in terms which have any human value, and though it may receive out purely intellectual credence it cannot be woven into the pattern of life as it is led, in contradistinction to life as we attempt to think about it. Vibrations in the either are so totally unlike, let us say, the color purple that the gulf between them cannot be bridged, and they are, to all intents and purposes, not one but two separate things of which the second and less "real" must be the most significant for us. And just as the sensation which has led us to attribute an objective reality to a nonexistent thing which we call "purple" is more important for human life than the conception of vibrations of a certain frequency, so too the belief in God, however ill founded, has been more important in the life of man than the germ theory of decay, however true the latter may he. We may, if we like, speak of consequence, as certain mystics love to do, of the different levels or orders of truth. We may adopt what is essentially a Platonist trick of thought and insist upon postulating the existence of external realities which correspond to the needs and modes of human feeling and which, so we may insist, have their being is some part of the universe unreachable by science. But to do so is to make an unwarrantable assumption and to be guilty of the metaphysical fallacy of failing to distinguish between a truth of feeling and that other sort of truth which is described as a "truth of correspondence," and it is better perhaps, at least for those of us who have grown up in an age of scientific thought, to steer clear of such confusions and to rest content with the admission that, though the universe with which science deals is the real universe, yet we do not and cannot have any but fleeting and imperfect contacts with it ; that the most important part of our lives-our sensations, emotions, desires, and aspirations-takes place in a universe of illusions which science can attenuate or destroy, but which it is powerless to enrich.

单选题Cancer cells destroy not only all rival cells, in their ruthless biological warfare, but also destroy the larger organization—the body itself—signing their own suicide warrant. A. refined B. random C. merciless D. perpetual

单选题In bringing up children, every parent watches eagerly the child's acquisition(学会)of each new skill—the first spoken words, the first independent steps, or the beginning of reading and writing. It is often tempting to hurry the child beyond his natural learning rate, but this can set up dangerous feelings of failure and states of worry in the child. This might happen at any stage. A baby might be forced to use a toilet too early, a young child might be encouraged to learn to read before he knows the meaning of the words he reads. On the other hand, though, if a child is left alone too much, or without any learning opportunities , he loses his natural enthusiasm for life and his desire to find out new things for himself. Parents vary greatly in their degree of strictness towards their children. Some may be especially strict in money matters. Others are severe over times of coming home at night or punctuality for meals. In general, the controls imposed represent the needs of the parents and the values of the community as much as the child's own happiness. As regards the development of moral standards in the growing child, consistency is very important in parental teaching. To forbid a thing one day and excuse it the next is no foundation for morality(道德). Also, parents should realize that "example is better than precept". If they are not sincere and do not practise what they preach(说教), their children may grow confused, and emotionally insecure when they grow old enough to think for themselves, and realize they have been to some extent fooled. A sudden awareness of a marked difference between their parents' principles and their morals can be a dangerous disappointment.

单选题For most of the 20th century, Asia asked itself what it could learn from the modern, innovating West. Now the question must be reversed. What can the West's overly indebted and sluggish (经济滞涨的) nations learn from a nourishing Asia? Just a few decades ago, Asia's two giants were stagnating (停滞不前) under faulty economic ideologies. However, once China began embracing market economy reforms in the 1980s, followed by India in the 1990s, both countries achieved rapid growth. Crucially, as they opened up their markets, they balanced market economy with sensible government direction. As the Indian economist Amartya Sen has wisely said, "The invisible hand of the market has often relied heavily on the visible hand of government." Contrast this middle path with America and Europe, which have each gone ideologically over-board in their own ways. Since the 1980s, America has been increasingly clinging to the ideology of uncontrolled free markets and dismissing the role of government—following Ronald Regan's idea that "government is not the solution to our problem; government is the problem". Of course, when the markets came crashing down in 2007, it was decisive government intervention that saved the day. Despite this fact, many Americans are still strongly opposed to "big government". If Americans could only free themselves from their antigovernment doctrine, they would begin to see that the America's problems are not insoluble. A few sensible federal measures could put the country back on the right path. A simple consumption tax of, say, 5% would significantly reduce the country's huge government deficit without damaging productivity. A small gasoline tax would help free America from its dependence on oil imports and create incentives for green energy development. In the same way, a significant reduction of wasteful agricultural subsidies could also lower the deficit. But in order to take advantage of these common-sense solutions, Americans will have to put aside their own attachment to the idea of smaller government and less regulation. American politicians will have to develop the courage to follow what is taught in all American public-policy schools: that there are good taxes and bad taxes. Asian countries have embraced this wisdom, and have built sound long-term fiscal (财政的) policies as a result. Meanwhile, Europe has fallen prey to a different ideological trap: the belief that European governments would always have infinite resources and could continue borrowing as if there were no tomorrow. Unlike the Americans, who felt that the markets knew best, the Europeans failed to anticipate how the markets would react to their endless borrowing. Today, the European Union is creating a $580 billion fund to ward off sovereign collapse. This will buy the EU time, but it will not solve the bloc's larger problem.

单选题I know it may rain tomorrow, but I am going home ______.

单选题The tree, the branches ______ are almost bare, is a very old one. A. whose B. in which C. of which D. which