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2012届高考英语二轮专题复习精品阅读理解部分之限时训练（四）

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A breathtaking trick potentially left over from our ancestors might be found in us — the ability to sense oxygen through our skin.

Amphibians(两栖动物), animals such as frogs that can live both on land and in water, have long been known to be capable of breathing through their skin. In fact, the first known lungless frog that breathes only through its skin was discovered recently in the rivers of Borneo.

Now the same oxygen sensors found in frog skins and in the lungs of mammals have unexpectedly been discovered in the skin of mice.

“No one had ever looked,” explained Randall Johnson, a biologist researcher. Mice and frogs are quite distant relatives, so the fact they have these molecules (分子) in common in their skin suggests they might well be found in the skin of other mammals, such as humans.

“We have no reason to think that they are not in the skin of people too,” Johnson said.

These molecules not only detect oxygen, but help increase levels of vital red blood cells, which carry oxygen around the body. Normal mice breathing in air that is 10 percent oxygen—a dangerously low level similar to conditions at the top of Mount Everest, and about half that of air at sea level. However, mice that had the oxygen sensor HIF-1 a genetically removed from their skin failed to produce this hormone (荷尔蒙) even after hours of such low oxygen.

These findings, if they hold true in humans, suggest one could raise the level of oxygen circulating inside the body. This could help treat lung diseases and disorders such as anemia (贫血症) without injecting drugs, which make up a multibillion-dollar market, Johnson said.

Athletes also often try to get more oxygen delivered to their muscles in order to improve their performance. They often do this by training at high altitudes or in low-oxygen tents. The new study suggests they might want to expose their skin as well as breathing in low-oxygen air to improve their performance. “It’s hard to say what exactly might be done, however—there’s a lot we don’t know yet,” Johnson explained.

The scientists detailed their findings in the April 18 issue of the journal Cell. 64. Which of the following statements is TRUE according to the passage? A. Johnson believes that oxygen sensors also exist in human skin. B. People have to surf the Internet to read detailed findings.

C. It has been proved that these findings help treat lung diseases D. It has long been expected oxygen sensors exist in mice’s skin. 65. One of the functions of the molecules mentioned above is _______.

A. carrying oxygen around the body B. improving athletes’ performance C. detecting oxygen

D. increasing level of oxygen

66. What is Johnson’s attitude to the application of the findings to the athletes’ training?

A. Negative B. Doubting C. Positive D. Hesitating

67. The best title of the passage may be _______. A. Great Findings Benefit Athletes A Lot B. Frogs And Mice Are Distant Relatives C. First Known Animal Breathes Through Skin D. Humans Might Sense Oxygen Through Skin 完形填空（共20小题；每小题1分，满分20分）

A farmer had some puppies (小狗) he needed to sell. He painted a sign 36 the puppies and set about nailing it to a post on the 37 of his yard. As he was 38 the last nail into the post, he felt a pull on his clothes. He looked down 39 the eyes of a little boy.

“Mister,” he said, “I want to buy one of your puppies. ”

“ 40 ,” said the farmer, as he rubbed the sweat off the back of his neck, “these puppies come from fine 41 and cost much money. ”

The boy dropped his head for a moment. Then reaching 42 into his pocket, he pulled out a 43 of coins and said to the farmer. “I've got thirty-nine cents. Is that enough to take a look? ” “Sure, ” said the farmer, and with that he 44 a whistle, “Here, Dolly! ” he called.

45 from the doghouse ran Dolly followed by four little balls of fur. The little boy 46 his face against the chain link fence. His eyes danced with 47 .

As the dogs made their 48 to the fence, the little boy noticed something else. Another little ball appeared, obviously 49 . In a somewhat 50 manner the little puppy began hobbling toward the others, doing its best to catch up with others. “I want that one, ” the little boy said, pointing to it.

The farmer 51 down at the boy's side and said, “Son, you don't. He will never be able to run and play with you like these other dogs. ”

52 that the little boy stepped back from the fence, 53 down, and began rolling up one leg of his trousers. In doing so he exposed a steel brace(支持物) attaching itself to a 54 made shoe. Looking up, he said, “You see sir, I don't run too well myself, and he will need someone who understands. ”

Yes, the world is full of people who need someone who 55 .

36. A. introducing B. showing C. advertising D. explaining 37. A. back B. edge C. center D. top

38. A. driving B. pushing C. entering D. taking 39. A. to B. on C. for D. into

40. A. Certainly B. Well C. Sorry D. Likely

41. A. parents B. friends C. relatives D. customers 42. A. deeply B. deep C. wide D. widely 43. A. number B. piece C. handful D. deal

44. A. went out B. took out C. let out D. found out

45. A. Away B. Far C. Out D. Into

46. A. felt B. placed C. pushed D. pressed 47. A. tears B. delight C. fear D. sorrow 48. A. way B. direction C. path D. route

49. A. whiter B. fatter C. thinner D. slower 50. A. awkward B. forward C. smart D. interesting 51. A. looked B. lay C. pointed D. knelt 52. A. For B. In C. About D. With 53. A. reached B. arrived C. lay D. put

54. A. specially B. especially C. exactly D. naturally 55. A. loves B. understands C. shares D. cares 任务型阅读：请认真阅读下面短文，在表格中的空格里填上最恰当的单词(每空1个单词) Since the beginning of human evolution, men have migrated（迁移）across continents in search of food, shelter, safety, and comfortable weather. People still move for these reasons, but new reasons for human migration are arising, such as job relocation(重新安置) and overpopulation.

Three million migrants are moving from poor countries to wealthier ones each year, and increasingly, their destination is a neighboring country in developing parts of the world. People are moving within the developing world for the same reasons as they migrate to wealthier nations. People from poor countries are going to less poor countries, fleeing wars and conflicts. They are also responding to population pressures because some countries are densely populated, and they often have high population growth. Those people need to go somewhere else.

There are three main reasons why people move. The basic categories and percentages are as follows, according to the Current Population Surveys (CPS):

Family-related reasons account for 26.3%, including changes in marital（婚姻的） status, establishing a household and other family reasons; work-related reasons 16.2%, including job transfer, retirement, and other job-related reasons; housing-related reasons 51.6%, including new and better houses, better neighborhood, cheaper housing and other housing reasons; the remaining 5.9% of other reasons are attending college, the change of climate and health reasons.

Americans have been migrating south and west for decades in search of better job opportunities and warmer climates. They have also been moving to places a little far from cities, in search of bigger yards and houses, lower crime rates and better schools. In 1950, nearly a fifth of the population lived in the nation’s 20 largest cities. In 2006, it was about one in ten. That’s why many American people say, “Big Cities Shrink as People Move South, West.”

Between March 2005 and March 2007, 73.4 million Americans moved. Fifty-six percent of these moves were within the same country. Twenty percent were between counties but in the same state. Nineteen percent were moves to a different state. Some families even went abroad.

Title: People on the 71 Lead-in Throughout human 72 , people have migrated across continents.