单选题Think of the ocean on a calm day. Ignoring the rise and fall of the waves, you might imagine the surface was dead flat the whole way across. You'd be wrong. Hills and valleys are as much as a feature of the sea as the land, although on a much smaller scale. These undulations have a variety of causes. Tides, currents, eddies, winds, river flow and changes in salinity and temperature push the sea level up in some places and down in others by as much as 2 meters. Ever tried swimming uphill? How do we map these oceanic hills and valleys? First, we need to know what the planet would look like without them. This is where the geoid (大地水准面) comes in. It is a surface where the Earth's gravitational potential is equal and which best fits the global mean sea level. It is approximately an ellipsoid, though uneven distribution of mass within the Earth means that it can vary from this ideal by up to 150 meters. The geoid represents the shape the sea surface would be if the oceans were net moving and affected only by gravity. Thus it can be used as a reference to measure any deviations in the ocean surface height that aren't caused by gravity—the hills and valleys, for instance, or any regional increase in sea level. So how do you measure the geoid and the ocean's irregular topography? It's complicated. Geophysicists calculate the geoid using data on variation in gravitational acceleration from several dozen satellites. The hills and valleys of the oceans are all very interesting, but can the geoid tell us anything more significant about the state of the planet? It certainly can. Knowing accurately where the geoid lies and how the Ocean surface deviates from it will help meteorologists spot changes in Ocean currents associated with climate change. The circumpolar current around Antarctic is one they are particularly interested in. It can also predict local climate variations produced by events such as El Nino, El Nino keeps warm water that would normally move westwards close to the coast of South America, deprives Southeast Asia of its monsoon rains, and increases rainfall on the west coast of the Ametlca. Since temperature changes cause changes in sea level, geoid-watchers should be able to prepare us before it strikes.

单选题Brazilian music is thoroughly imbued with African themes, and illustrious composers have long found inspiration in the black musical heritage.

单选题(Electronic) mail to describe an upcoming workshop (should use) only (if) potential participants use this form of communication (regularly).

单选题______ some money，Jimmy was able to buy his mother a washing machine．

单选题In English poetry, a quatrain is____.

单选题Dean and Carolyn always put small presents in ______ stockings on Christmas Day.A. each other'sB. each otherC. each othersD. each others'

单选题All the staff members of the department made concerted efforts to ______ the hall for the Christmas party. A. clean up B. clear up C. dress up D. make up

单选题After taking office, China"s Prime Minister, Zhu Rongji, tried his best to promote the new ______ policies.

单选题The grammatical category which is used in the analysis of word classes to identify the syntactic relationship between words in a sentence is ______.

单选题An obvious change of attitude at the top towards women' s status in society will ______ through the current law system in that country. A. permeate B. violate C. probe D. grope

单选题If the struggle for a sustainable society _____, we must have some vision of what we are aiming for.

单选题We found the poetry (quite pleased) in (form); I (had) never seen one like (it) before. A. quite pleased B. form C. had D. it

单选题Pity those who aspire to put the initials PhD after their names. After 16 years of closely supervised education, prospective doctors of philosophy are left more or less alone to write the equivalent of a large book. Most social-science postgraduates have still not completed their theses by the time their grant runs out after three years. They must then get a job and finish in their spare time, which can often take a further three years. By then, most new doctors are sick to death of the narrowly defined subject, which has blighted their holidays and mined their evenings. The Economic and Social Research Council, which gives grants to postgraduate social scientists, wants to get better value for money by cutting short this agony. It would like to see faster completion rates: until recently, only about 25 % of PhD candidates were finishing within four years. The ESRC's response has been to stop PhD grants to all institutions where the proportion taking less than four years is below 10%; in the first year of this policy the national average shot up to 39%. The ESRC feels vindicated in its toughness, and will progressively raise the threshold to 40% in two years. Unless completion rates improve further, this would exclude 55 out of 73 universities and polytechnics-including Oxford University, the London School of Economics and the London Business School. Predictably, howls of protest have come from the universities, who view the blacklisting of whole institutions as arbitrary and negative. They point out that many of the best students go quickly into jobs where they can apply their research skills, but consequently take longer to finish their theses. Polytechnics with as few as two PhD candidates complain that they are penalized by random fluctuations in student performance. The colleges say there is no hard evidence to prove that faster completion rates result from greater efficiency rather than lower standards or less ambitious doctoral topics. The ESRC thinks it might not be a bad thing if PhD students were more modest in their aims. It would prefer to see more systematic teaching of research skills and fewer unrealistic expectations placed on young men and women who are undertaking their first piece of serious research. So in future its grants will be given only where it is convinced that students are being trained as researchers, rather than carrying out purely knowledge-based studies. The ESRC can not dictate the standard of thesis required by external examiners, or force departments to give graduates more teaching time. The most it can do is to try to persuade universities to change their ways. Recalcitrant professors should note that students want more research training and a less elaborate style of thesis, too.

单选题 "The highest merit we ascribe to Moses, Plato, and Milton," says Emerson, "is that they set at nought books and traditions, and spoke not what men thought but what they thought. A man should learn to detect and watch that gleam of light which flashes across his mind from within, more than the luster of the firmament of bards and sages. Yet he dismisses without notice his thought because it is his. In every work of genius we recognize our own rejected thoughts; they come back to us with a certain alienated majesty." It is strange that any one who has recognized the individuality of all works of lasting influence should not also recognize the fact that his own individuality ought to be steadfastly preserved. As Emerson says in continuation, "Great works of art have no more affecting lesson for us than this. They teach us to abide by our spontaneous impressions with goodhumored inflexibility, then most when the whole cry of voices is on the other side. Else tomorrow a stranger will say with masterful good sense precisely what we have thought and felt all the time, and we shall be forced to take with shame our opinion from another." Accepting the opinions of another and the tastes of another is very different from agreement in opinion and taste. Originality is independence, not rebellion. It is sincerity, not antagonism. Whatever you believe to be true and false, that proclaim to be true and false. Whatever you think admirable and beautiful, that should be your model, even if all your friends and all the critics storm at you as a crotchet-monger and an eccentric. Whether the public will feel its truth and beauty at once, or after long years, or never cease to regard it as paradox and ugliness, no man can foresee. Enough for you to know that you have done your best, have been true to yourself, and that the utmost power inherent in your work has been displayed.

单选题It is worthwhile to study the various ways in which Shakespeare used English because _________.

单选题Theringhasbeen______inmyfamily.Itwasmygreat-grandmother’soriginally.

单选题Some observers thought the war would be Ucalamitous/U.