单选题In the last few years, he has ______ projects with the United Nations to study environmental issues in developing countries.

单选题______ recent developments we do not think your scheme is practical.

单选题Betty saved her money ______ she might buy an MP3 player.

单选题"Would you like some tea?" "Yes, please, but just ______ . " A. few B. a few C. little D. a little

单选题I"d like to ______ this old car for a new model but I am afraid I cannot afford it.

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单选题(D) Is language, like food, a basic human need without which a child at a critical period of life can be starved and damaged? Judging from the experiment of Frederick Ⅱ in the thirteenth century, it may be. Hoping to discover what language a child would speak if he heard no mother tongue, he told the nurses to keep silent. All the babies died before the first year. But clearly there was more than lack of language here. What was missing was good mothering. Without good mothering, in the first year of life especially, the ability to survive is seriously influenced. Today no such severe lack exists as that ordered by Frederick Ⅱ Nevertheless, some children are still backward in speaking. Most often the reason for this is that the mother is insensitive (不敏感的) to the signals (信号) of the baby, whose brain is made to learn language rapidly. If these sensitive periods are neglected, the ideal time for acquiring skills passes and they might never be learned so easily again. A bird learns to sing and to fly rapidly at the right time, but the process is slow and hard once the critical stage has passed. Experts suggest that speech stages are reached in a fixed order and at a constant age, but there are cases where speech has started late in a child who eventually turns out to be clever. At twelve weeks a baby smiles and makes vowel-like sounds, at twelve months he can speak simple words and understand simple commands, at eighteen months he has a vocabulary of three to fifty words. At three he knows about 1000 words which he can put into sentences, and at four he knows his language differs from that of his parents in style rather than grammar.

单选题Another thunderstorm slammed ________ the mountain as I limped up the path to the house.

单选题I don"t know what ______ Alfred to read your letter, ______ he thought it was addressed to him.

单选题—Can you come on Monday or Tuesday? —I"m afraid ______ day is possible.

单选题Whoever fails to carry out his or her assigned tasks on time will be considered unreliable.

单选题 (A) When doctors need information about what dose of medicine to prescribe, they usually consult a fat blue book called the Physicians' Desk Reference, or PDR. But the doses recommended in the PDR may be too high for many people and may cause bad reactions, ranging from dizziness (头晕) and nausea(恶心)all the way to death, according to an article published last month in the journal Postgraduate Medicine. For many drugs, smaller doses would work just as well, with far less risk of bad reactions, said the author, Jay Cohen, an associate professor at the University of California. "Side effects drive a lot of people out of treatment that they need," Dr. Cohen said. "People often gave up trying to treat their illnesses when they found that the cure was worse than the disease. But if doctors were to individualize doses for each patient, more people might take their medicine. " Dr. Cohen said he became aware of the problem because he met many patients who suffered from side effects even though they had taken what were supposedly the correct doses of medicine. When Dr. Cohen consulted medical journals and textbooks, he discovered studies showing that many patients were helped by smaller than usual amounts of medicine. And many of his own patients did better with reduced doses. Dosing guidelines generally tend to be too high because they are based on studies conducted with limited numbers of patients by drug companies when they are seeking approval for new products, Dr. Cohen said. For those studies to run efficiently, doses need to be high enough to show as quickly as possible that the drug works. But later, after the drug is approved, far more people take it, sometimes along with other drugs, and individual differences begin to show up. That information does not always make it into the PDR, Dr. Cohen said. Dr. Cohen cautioned that patients should not try to change doses of prescription on their own. He said they needed to work with doctors to adjust the doses safely.

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单选题Quite different from storm waves are the giant sea waves called tsunamis, which derive their name from the Japanese expression for "high water in a harbor". These waves are also referred to by the general public as tidal waves, although they have relatively little to do with tides. Scientists often refer to them as seismic (地震的) sea waves, far more appropriate in that they do result from undersea seismic activity. Tsunamis often occur in the Pacific because the Pacific is an area of heavy seismic activity. Two areas of the Pacific well accustomed to the threat of tsunamis are Japan and Hawaii. Because the seismic activity that causes tsunamis in Japan often occurs on the ocean bottom quite close to the islands, the tsunamis that hit Japan often come with little warning and can therefore prove disastrous. Most of the tsunamis that hit the Hawaiian Islands, however, originate (起源) thousands of miles away near the coast of Alaska, so these tsunamis have a much greater distance to travel and the inhabitants of Hawaii generally have time for warning of their arrival. Tsunamis are certainly not limited to Japan and Hawaii. In 1755, Europe experienced a disastrous tsunami, when movement near the Azores caused a massive tsunami to sweep onto the Portuguese coast and flood the heavily populated area around Lisbon. The greatest tsunami on record occurred on the other side of the world in 1883 when the Krakatoa volcano (火山) underwent (经历) a massive explosion, sending waves more than 30 meters high onto nearby Indonesian islands, the tsunami from this volcano actually traveled around the world and was witnessed as far away as the English Channel.

单选题We will give the prizes to those whom we consider ______.

单选题Word got around ______ he had resigned his position as executive secretary of the committee.

单选题______ about his financial position that he couldn"t sleep at night.

单选题—The police think your brother John stole the diamond in the museum yesterday evening. —Oh? But he stayed with me at home the whole evening; he ______ the museum.

单选题Do you know how to use a mobile phone (手机) without being rude to the people around you? Talking during a performance irritates (激怒) people. If you are expecting an emergency call, sit near the exit doors and set your phone to vibrate (振动). When your mobile phone vibrates, you can leave quietly and let the others enjoy the performance. Think twice before using mobile phones in elevators, museums, churches or other indoor public places—especially enclosed spaces. Would you want to listen to someone"s conversation in these places? Worse yet, how would you feel if a mobile phone rang suddenly during a funeral! It happens more often than you think. Avoid these embarrassing situations by making sure your mobile phone is switched off. When eating at a restaurant with friends, don"t place your mobile phone on the table. This conveys the message that your phone calls are more important than those around you. Mobile phones have sensitive microphones that allow you to speak at the volume you would on a regular phone. This enables you to speak quietly so that others won"t hear the details of your conversations. If you are calling from a noisy area, use your hand to direct your voice into the microphone. Many people believe that they can"t live without their mobile phone. Owning a mobile phone definitely makes life more convenient, but limit your conversations to urgent ones and save the personal calls until you are at home.