单选题The aurora is one of nature's most ______ spectacles.

单选题Women have significant advantages over men in space because they need less food and less oxygen and they ______ radiation better. A. stand up to B. stand in for C. stand up for D. stand in with

单选题Sometimes the 3-year-old child has trouble ______ fact from fiction.

单选题She bought various ______ , which later reminded her of the trip to Thailand.

单选题After the concert, the clean-up crew found the ground ______ with papers, bottles and cans. A. scrubbed B. used C. littered D. dispersed

单选题The destruction of rainforests has been ______ as a disaster for the environment. A. blamed B. declared C. condemned D. appealed

单选题The judge's decision ______ Montez's hopes of receiving a reduced prison sentence.

单选题Jane and Tom have been able to {{U}}reconcile{{/U}} their difference and are a happy family again.

单选题Sarah: Hello. Im calling to rent an apartment you advertised.Manager: Yes. What kind of apartment are you interested in?Sarah: I m interested in a one-bedroom apartment. 56__________?Manager

单选题___ of the three sisters you choose to marry, you will have a good wife. 

单选题According to the passage, which of the following is TRUE?

单选题The boy's laziness ______ his failure in the exams.

单选题Bill is an example of a severely disabled person who has become ______ at many survival skills.

单选题Which of the following statement is NOT true?

单选题 Why the Earth's surface temperature hasn't warmed as expected over the past decade continues to be a puzzle for scientists. One study out earlier this month theorized that the Earth's climate may be less sensitive to greenhouse gases than currently assumed. Another surprising factor could be the amount of water vapor way up in the stratosphere (平流层), according to a new study out Thursday in the journal Science. 'Water vapor, a powerful, natural greenhouse gas that absorbs sunlight and re-emits heat, is 'a wild card' of global warming,' says the paper's lead author, senior scientist Susan Solomon of the National Oceanic and Atmospheric Administration. In the Science paper, Solomon and her colleagues found that a drop in the concentration of water vapor in the stratosphere 'very likely made substantial contributions to the flattening of the global warming trend since about 2000'. The decline in water vapor in the stratosphere slowed the rate of surface warming by about 25%, compared to that which would have occurred due to carbon dioxide and other greenhouse gases, notes the study. Specifically, the planet should have warmed 0.25 degree F during the 2000s, but because of the influence of the water vapor, it rose just 0.18 degree F. Why did the water vapor decrease? 'We really don't know,' says Solomon, 'We don't have enough information yet.' 'The findings are 'surprising',' says Bill Randel, an atmospheric chemist at the National Center for Atmospheric Research, who was not part of the study. He said it was surprising how big an effect such a very little change in stratospheric water vapor has had on the surface climate. These fluctuations in water vapor could be part of a feedback loop. Although it's known that water vapor in the troposphere (对流层) increases as the climate warms—and is a major climate feedback that is well simulated in global climate models—in sharp contrast, models do a poor job of simulating water vapor in the stratosphere, according to the paper. But Solomon points out this isn't an indication that predictions on global warming are overstated: 'This doesn't mean there isn't global warming,' notes Solomon. 'There's no significant debate that it is warmer now than it was 100 years ago, due to anthropogenic (人造的) greenhouse gases.' And how will this water vapor affect future global warming? 'We really don't know the answer to this,' says Solomon. 'If the water changes are due to the specific way the sea-surface temperature pattern looks right now, then it may well not be linked to the overall warming. It could just be a source of variability from one decade to another as the ocean pattern slowly changes. Or it could be linked to the overall warming of the tropics, in which case it could continue to 'put the brakes on'. Only time will tell, and more data.'

单选题We will also see a______increase in the number of televisions per household, as small TV displays are added to clocks, coffee makers and smoke detectors.

单选题When a person dies, his debts must be paid before his ______ can be distributed.

单选题W: You haven’t seen a blue notebook, have you? I hope I didn’t leave it in the reading room.M: Did you check that pile of journals you’ve borrowed from the library the other day?Q: What is the man trying to say to the woman?

单选题Scarcely ______ down when ______ a knock at the door. A．had he sat; did he hear B．he had sat; did he hear C．he had sat; he heard D．had he sat; he heard

单选题For many people, overeating and overspending are as ______ to Christmas as candles and holly.