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1、北京地区成人本科学士学位英语统一考试2013.05.11Passage 1Is that 6 a.m. workout getting in the way of good sleep? Dont think your fat cells wont notice. A new study published in The Annals of Internal Medicine (a medical journal) finds that inadequate shut-eye has a harmful effect on fat cells, reducing their ability t
2、o respond to insulin (胰岛素) by about 30 percent. Over the long-term, this decreased response could set the stage for type-2 diabetes (a medical condition in which someone has too much sugar in his or her blood), fatty liver disease and weight gain.The study adds to a growing body of evidence that the
3、re “an intimate relationship between the amount of sleep we get and our ability to maintain a good, healthy body weight,” says sleep expert Helene Emsellem, director of the Center for Sleep and Wake Disorders in Chevy Chase, Maryland. (76) But Americans dont seem to be getting the message that we ne
4、ed seven to nine hours par night. More than 1 in 5 of us, according to a report from the Centers for Disease Control and Prevention, is getting six or fewer hours of sleep per night, on average.So how did researchers study fat cells in the Annals paper? Matthew Brady of the University of Chicago and
5、 a group of colleagues selected and persuaded seven volunteers to take part in the research project. They were all young, thin and healthy and agreed to sleep for eight nights in a sleep lab. “For four nights they were allowed to stay in bed for 8.5 hours a night,” says Brady. Then, a month later, t
6、hey came back for four additional nightsbut this time they were allowed just 4.5 hours of sleep per night. And after each visit, researchers got a sample of their fat. (77) Brady explains that the fat cells responded significantly to the loss of sleep. “I was very surprised to be honest,” he says.Ba
7、d things can happen when fat cells become less responsive to insulin. “Fat cells are actually your friend,” he says. “Theyre there to store lipids (血脂).” When lipids stay inside the cells, your body can utilize the fat when youre exercising or sleeping or going about your day. “However, when fat cel
8、ls stare to become insulin resistant, the lipids star to leach out of the fat cells and rise in the bloodstream,” Brady says.1. According to the passage, lack of sleep for a long while can probably lead to all of the following EXCEPT_.A. heart diseaseB. weight gainC. diabetesD. liver disease2. The m
9、ain idea of the third paragraph is_A. how to write a medical research paperB. how to avoid sleep lossC. how the research was conductedD. how to conduct a medical experiment3. What does the “leach” in the last paragraph probably mean?A. Leap. B. Lead.C. Lean. D. Leak.4. Which of the following is NOT
10、TRUE according to the passage?A. We will be in trouble if our fat cells become less responsive to insulin.B. More and more studies are done to study the lind between sleep and weight.C. More than 20% of Americans are not getting enough sleep.D. Fat cells are there to help us maintain a good health.5
11、. Which of the following is an appropriate title for this passage?A. Poor Sleep May Lead to Too Much Stored Fat and DiseaseB. Sleep Experts Had Exciting Findings in a Fat StudyC. Americans Should Have More Than Six Hours of SleepD. Bad Things Happen if Fat Cells Become Our FriendPassage 2The top of
12、the world is a wonderland. In winter, the temperature often falls to -30F and the sun never rises. The ocean is surrounded by frozen ground. There are few people or trees, but to polar bears, the Arctic(北极)is home.(78) Polar bears have thick fur, big paws and other features that make them well prepa
13、red for life in their tough environment. In fact, they need the Arctic sea ice for survival. But climate change is causing larger and larger areas of summer sea ice to melt(融化). Experts say that if warming patterns continue, the Arctic could be free of summer sea ice by 2050. That may cause two-thir
14、ds of the worlds 20,000 polar bears to be gone by then too.Polar bears cant survive for long on land. Seals are their main source of food. The only place where polar bears can hunt seals is on the ice. (79) Although these bears are strong swimmers, they are no match for lightning swift seals in the
15、water. A polar bear has brilliantly clever strategies to overcome this disadvantage. In winter the bear waits motionless beside a seals breathing hole, which is a narrow tunnel through the ice. Often many hours pass before the seal comes up for air and the bear kills it with a powerful blow of its p
16、aw. In summer, the polar bears that live on land eat very little and wait for the sea ice to return.With the sea ice forming later in the year and melting earlier, polar bears do not have enough opportunity to hunt and eat. Less sea ice makes it harder for the bears to catch the seals. The bears must swim longer distances between ice packs(大片浮冰),and they cant always make it. The ice is also getting thinner. These conditions can cause polar-bear cabs to become separated from
