单选题Variables such as individual and corporate behavior______nearly impossible for economists to forecast economic trends with precision.

单选题Mergers may be effective to revive or rejuvenate failing business by the {{U}}infusion{{/U}} of new management and personnel. A. inspection B. introduction C. evaluation D. concentration

单选题Now a paper in Science argues that organic chemicals in the rock come mostly from ______ on earth than bacteria on Mars.

单选题 There are few more sobering online activities than entering data into college-tuition calculators and gasping as the Web spits back a six-figure sum, But economists say families about to go into debt to fund four years of partying, as well as studying, can console themselves with the knowledge that college is an investment that, unlike many bank stocks, should yield huge dividends. A 2008 study by two Harvard economists notes that the "labor-market premium to skilr " —or the amount college graduates earned that's greater than what high-school graduates earned—decreased for much of the 20th century, but has come back with a vengeance since the 1980s. In 2005, the typical full-time year-round U.S. worker with a four-year college degree earned $ 50,900, 62% more than the $ 31,500 earned by a worker with only a high-school diploma. There's no question that going to college is a smart economic choice. But a look at the strange variations in tuition reveals that the choice about which college to attend doesn't come down merely to dollars and cents. Does going to Columbia University (tuition, room and board $ 49,260 in 2007-2008) yield a 40% greater return than attending the University of Colorado at Boulder as an out-of-state student( $ 35,542)? Probably not. Does being an out-of-state student at the University of Colorado at Boulder yield twice the amount of income as being an in-state students( $17,380) there? Not likely. No, in this consumerist age, most buyers aren't evaluating college as an investment, but rather as a consumer product—like a car or clothes or a house. And with such purchases, price is only one of many crucial factors to consider. As with automobiles, consumers in today's college marketplace have vast choices, and people search for the one that gives them the most comfort and satisfaction in line with their budgets. This accounts for the willingness of people to pay more for different types of experiences(such as attending a private liberal-arts college or going to an out-of-state public school that has a great marine-biology program). And just as two auto purchasers might spend an equal amount of money on very different cars, college students(or, more accurately, their parents)often show a willingness to pay essentially the same price for vastly different products. So which is it?

单选题Since most, if not all learning occurs through ______, relating one observation to another, it would be strange indeed if the study of other cultures did not also illuminate the study of our town. A. assumptions B. experiments C. comparisons D. repetitions

单选题A full-sized tripod is far too ______ to carry around. I find this pocket-sized one is much handier.

单选题Ever since the rise of industrialism, education has been______towards producing workers.

单选题A historical novel may do more than mirror history; ______ future events.

单选题The aim of their revolution is to leave scientists free to continue research, ______ by any regulation.

单选题Do help yourself to some fruit, ______you?

完形填空Cloze 1 Someday a stranger will read your e-mail without your permission or scan the websites youve visited

完形填空Cloze 1 Historically, humans get serious about avoiding disasters only after one has just struck them

完形填空Most worthwhile careers require some kind of specialized training

完形填空Cloze 2 In study after study, four traits are typical of happy people

完形填空Researchers have found more evidence that hostility can 21 ________ to heart disease, according to a report in the current issue of the journal Psychosomatic Medicine

完形填空Zoos have become an important site for the preservation and protection of wildlife resources, (1) ________ thosespecies that are endangered

完形填空Cloze 2 When Spanish football club Barcelona paid US$35 million for Ronaldinho last summer, they werent buying a pretty face

完形填空On a single weekend last month, there were three serious highway accidents in this country that 21 ________teenageddrivers

完形填空The list of ills attributable to obesity keeps growing: Last week, obese people were accused of causing global warming

完形填空Ways of shopping for goods have changed a lot in the last 50 years