单选题New data has ______ that the damage to the ozone layer is not confined to the southern hemisphere. A. ratified B. confirmed C. assured D. approved

单选题After several years of isolation on the deserted island, he began to ______ of ever getting back home.

单选题He didn't notice me in the crowd, but he spotted my sister who was ______ because other red hair.(2004年上海理工大学考博试题)

单选题From Paragraph 5 the author emphasizes ______.

单选题The foreign minister would reveal nothing about his recent tour of the Middle East {{U}}beyond{{/U}} what had already been announced at the press conference.

单选题According to the passage, alcohol has something to do with bad breath mainly because ______.

单选题I didn"t need any specific medical input or ______ control, although I was in a mess physically and I did need to rest, relax, and recharge myself.

单选题He leaned out of an upstairs window and felt a current of warm air______from the street.(2013年3月中国科学院考博试题)

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It is said that science has become too complex to acknowledge the existence of uni versal truths. A. address B. declare C. affirm D. Perceive

单选题The Uplainer/U a bowerbird's plumage, the more brightly it decorates its nest to attract a mate.

单选题To which one of the following questions does the author provide enough information to formulate an answer?

单选题The each revolves both round the sun and on its own axis.

单选题Smoking makes one six times more likely to get oral cancer partly because the smoke constantly assaults the tissues that line the mouth and throat.

单选题Henry Tanner received widespread recognition for his naturalistic paintings of plantation life. A. profits B. storage C. attention D. invitations

单选题The terms wad and frog refer to two different animals belonging to different genuses, and careful students ______ the two.

单选题Questions 27—30 are based on a report about generation gap. You now have 20 seconds to read Questions 27—30.

单选题In my opinion Elizabeth and Henry are not ______ friends as lovers.

单选题What is the author's attitude towards doctors?

单选题It's all annual back-to-school routine. One morning you wave goodbye, and that (56) evening you're burning the late-night oil in sympathy. In the race to improve educational standards, (57) are throwing the books at kids. (58) elementary school students are complaining of homework (59) . What's a well-meaning parent to do? As hard as (60) may be, sit back and chill, experts advise. Though you've got to get them to do it, (61) helping too much, or even examining (62) too carefully, you may keep them (63) doing it by themselves. "I wouldn't advise a parent to check every (64) assignment," says psychologist John Rosemond, author of Ending the Tough Homework. "There's a (65) of appreciation for trial and error. Let your children (66) the grade they deserve. " Many experts believe parents should gently look over the work of younger children and ask them to rethink their (67) . But "you don't want them to feel it has to be (68) ," she says. That's not to say parents should (69) homework first, they should monitor how much homework their kids (70) . Thirty minutes a day in the early elementary years and an hour in (71) four, five, and six is standard, says Rosemond. For junior-high students it should be " (72) more than an hour and a half," and two for high school students. If your child (73) has more homework than this, you may want to check (74) other parents and then talk to the teacher about (75) assignments.