单选题There are hidden factors which scientists call "feedback mechanisms". No one knows quite how they will interact with the changing climate. Here's one example: plants and animals adapt to climate change over centuries. At the current estimate of half a degree centigrade of warming per decade, vegetation may not keep up. Climatologist James Hansen predicts climate zones will shift toward the poles by 50 to 75 kilometers a year--faster than trees can naturally migrate. Species that find themselves in an unfamiliar environment will die. The 1000-kilometer-wide strip of forest running through Canada, Russia, and Scandinavia could be cut by half. Millions of dying trees would soon lead to massive forest fires, releasing tons of CO2 and further boosting global warming. There are dozens of other possible "feedback mechanisms". Higher temperatures will fuel condensation and increase cloudiness, which may actually damp down global warming. Others, like the "albedo" effect is the amount of solar energy reflected by the earth's surface. As northern ice and snow melts and the darker sea and land pokes through, more heat will be absorbed, adding to the global temperature increase. Even if we were to magically stop all greenhouse-gas emissions tomorrow the impact on global climate would continue for decades. Delay will simply make the problem worse. The fact is that some of us are doing quite well the way things are. In the developed world prosperity has been built on 150 years of cheap fossil fuels. Material progress has been linked to energy consumption. Today 75 percent of all the world's energy is consumed by a quarter of the world's population. The average rich-world resident adds about 3.2 tons of CO2 yearly to the atmosphere, more than four times the level added by each Third World citizen. The US, with just seven percent of the global population, is responsible for 22 percent of global warming.

单选题You have to be pretty dumb to be ______ in by an offer like that.

单选题Since any answer was likely to cause embarrassment to his party, the politician tried to ______ the question. A. evade B. delude C. seclude D. invade

单选题I ______ to one daily newspaper and one weekly magazine.

单选题People were surprised to find that he had the ability to ______everything he was involved in.

单选题Everybody likes him. He is very ______ with all his colleagues.

单选题Climatic conditions are delicately adjusted to the composition of the Earth's atmosphere. If there were a change in the atmosphere--for example, in the relative proportions of atmosphere gases--the climate would probably change also. A slight increase in water vapor, for instance, would increase the hem-retaining capacity of the atmosphere and would lead to a rise in global temperatures. In contrast, a large increase in water vapor would increase the thickness and extent of the cloud layer, reducing the mount of solar energy reaching the Earth' surface. The level of carbon dioxide, CO2 in the atmosphere has important effect on climatic change. Most of the Earth's incoming energy is short-wavelength radiation, which tends to pass through atmospheric CO2 easily. The Earth, however, reradiates much of the received energy as a long-wavelength radiation, Which CO2 absorbs and then remits toward the Earth. This phenomenon, known as the greenhouse effect, can result in an increase in the surface temperature of a planet. An extreme example of the effect is shown by the Venus, a planet covered by heavy clouds composed mostly of CO2, whose surface temperatures have been measured at 430℃. If the CO2 content of the atmosphere is reduced, the temperature falls. According to one respectable theory, if the atmospheric CO2 concentration were halved, the Earth would become completely covered with ice. Another equally respectable theory, however, states that a halving of the CO2 concentration would lead only to a reduction in global temperatures of 3℃. If, because of an increase in forest fires or volcanic activity, the CO2 content of the atmosphere increased, a warmer climate would be produced. Plant growth, which relies on both the warmth and the availability of CO2, would probably increase. As a consequence, plants would use more and more CO2. Eventually CO2 levels would diminish and the climate, in turn, would become cooler. With reduced temperatures many plants would die; CO2 would thereby be returned to the atmosphere and gradually the temperatures would rise again. Thus, if this process occurred, there might be a long-term oscillation in the amount of CO2 present in the atmosphere, with regular temperature increase and decrease of a set magnitude. Some climatologists argue that the burning of fossil fuels has raised the level of CO2 in the atmosphere and has caused a global temperature rise of at least 1℃. But a supposed global temperature rise of 1℃ may in reality be only several regional temperature increase, restricted to areas where there are many meteorological stations and caused simply by shifts in the pattern of atmospheric circulation. Other areas, for example the Southern Hemisphere oceanic zone, may be experiencing an equivalent temperature decrease that is unrecognized because of the shortage of meteorological recording stations.

单选题Your excuse that an elephant fell on you and made you late is just ______. A. inevitable B. indispensable C. incredible D. incurable

单选题Some psychologists argue that the traditional idea "spare the rod and spoil the child" is not rational .

单选题Hearing the news, she could feel anger______inside her.(2013年10月中国科学院考博试题)

单选题3 Forget football. At many high schools, the fiercest competition is between Coke and Pepsi over exclusive "pouring rights" to sell on campus. But last week Jeffrey Dunn, president of Coca-Cola Americas, called a timeout. Coke's machines will now also stock water, juice, and other healthful options--even rival brands and their facades will feature school scenes and other "noncommercial graphics" instead of Coke's vivid red logo. "The pendulum needs to swing back" on school-based marketing, said Dunn. Coke's about-face—-particularly the call to end the exclusive deals that bottlers make with school districts—comes amid rising concern over kids' health. American children are growing ever more obese and developing weight-related diseases usually found in adults. While inactivity and huge helpings factor heavily, a recent study in the Lancet fingered so da pop as a likely culprit. Communities--and legislators--are already on the case. Last year, for instance, parents in Philadelphia detailed a proposed contract with Coca-Cola that would have netted the school system $ 43 million over 10 years. And in a searing report to congress last month, the U. S. Department of Agriculture recommended that all snacks sold in schools meet federal nutrition standards (the requirements are loose enough that Snickers bars qualify). Spare change? Activists hope Coke's capitulation will help curb commercialism in schools altogether. From ads on Channel One, which broadcasts current-affairs programs on classroom TV, to middle-school math texts that cite Nike and other brand-name prod ucts in their word problems, to company-sponsored scoreboards on football fields, Ameri can pupils are bombarded. But Andrew Hagelshaw, executive director of the Oakland, Ca lif.-based Center for Commercial-Free Public Education, views Coca-Cola's policy shift as a "partial victory". Schools sign contracts with local bottlers; the parent company can only urge them to back off. Moreover, Coke's machines will remain in place, although with healthier options. And don't expect teenagers to suddenly swear off the stuff--or school districts to give up the revenue. At Wheeler High School in Marietta, Ga., where students arrive before 7 a. m. and stay as late as 11 o'clock at night, they rely on the machines. And the $ 50,000 in annual vending revenues have enabled Principal Joe Boland to refinish the gym floor, in stall a new high jump pit, and pay $ 7,000 for two buses. "If someone made an offer to me to take the machines out, I'd consider it," says Boland. "But nobody's offering me any money. /

单选题New technology links the world as never before. Our planet has shrunk. It's new a "global village" where countries are only seconds away by fax or phone or satellite link. And, of course, our ability to benefit from this high-tech communications equipment is greatly enhanced by foreign language skills. Deeply involved with this new technology is a breed of modem businesspeople who have a growing respect for the economic value of doing business abroad. In modem markets, success overseas often helps support domestic business efforts. Overseas assignments are becoming increasingly important to advancement within executive ranks. The executive stationed in another country no longer need fear being "out of sight and out of mind". He or she can be sure that the overseas effort is central to the company's plan for success, and that promotions often follow or accompany an assignment abroad, if an employee can succeed in a difficult assignment overseas, superiors will have greater confidence in his or her ability to cope back in the United States where cross-cultural considerations and foreign language issues are becoming more and prevalent(普遍的). Thanks to a variety of relatively inexpensive communications devices with business applications, even small businesses in the United States are able to get into international markets. English is still the international language of business. But there is an ever-growing need for people who can speak another language. A second language isn't generally required to get a job in business, but having language skills gives a candidate the edge when other qualifications appear to be equal. The employee posted abroad who speaks the country's principal language has an opportunity to fast-forward certain negotiations, and can have the cultural insight to know when it is better to move more slowly. The employee at the home office who can communicate well with foreign clients over the telephone or by fax machine is an obvious asset to the firm.

单选题A complete investigation into the causes of the accident should lead to improved standards and should ______ new operating procedures. A. result in B. match with C. subject to D. proceed with

单选题They awoke to find the maid had left the Uremnants/U of dinner on the table.

单选题The United States Capitol building, in Washington, D. C. , is set in a small park surrounded by a number of impressive government buildings.

单选题A woman enters a hospital ward determined to torture the comatose wife of her ex-lover and ______him for herself.

单选题Often considered in common thought as ______, language, culture, and personality are in fact inseparable.