A man does not know the difficulty of anything _______ he does it personally.

III. 完形填空（20%）
In order to be a success in the American business world, you must “get along” with people. You must learn to behave yourself in a way ___31___ you earn the affection (喜爱)and respect of others. ___32___ we have already pointed out, Americans ___33___ business and pleasure. Therefore, learning how to ___34___ informally can be a help with your American business___35___. Americans like to talk about a number of different ___36___—sports, politics, cars, popular movies and television shows and personal interests.
Many large American cities have sports teams. If you are ___37___ with Americans in the United States, it would be a good idea to ___38___ out about the local sports teams so that you can ___39___ the almost inevitable (不可避免的) discussions about “what our ___40___ will do this year.” Politics can be a ___41___ topic unless everyone is of the same mind ___42___. Limit your discussions to asking questions of your friends. Most Americans are ___43___owners and some are even crazy about the subject. You can participate___44___ talking about cars you have owned or by __45___information you have read in automotive magazines. Americans watch television almost every night and attend movies regularly, ___46___ naturally TV programs and the ___47___ movies become topics for discussions. If you are unable to ___48___ American television or attend American movies, reading the ___49___section of such magazine as Time and Newsweek will keep you up to date on ___50___ is popular in America.
31. A. which          B. where           C. how                  D. that
32. A. While          B. Since                C. As                    D. Because
33. A. mix             B. enjoy                C. like                   D. manage
34. A. conduct              B. appear           C. behave                 D. chat
35. A. friends         B. efforts           C. contacts             D. companies
36. A. persons        B. titles                 C. businesses          D. topics
37. A. meeting              B. working            C. living            D. playing
38. A. find             B. learn                 C. go                    D. stay
39. A. work on      B. join in           C. succeed in         D. break in
40. A. group          B. business            C. company           D. team
41. A. common      B. sensitive            C. special                 D. daily
42. A. politically    B. economically     C. professionally    D. personally
43. A. house          B. car                    C. business            D. land
44. A. in            B. toward                 C. by                    D. through
45. A. collecting     B. sharing              C. gathering           D. analyzing
46. A. so           B. but                   C. however            D. moreover
47. A. most interesting   B. most exciting     C. newest              D. latest
48. A. witness        B. look                  C. watch            D. glance
49. A. entertainmentB. sports           C. business            D. movie
50. A. which          B. that                   C. what                 D. as

Burning the midnight oil before an exam or interview has an opposite effect according to a research which found that sleep is necessary for memories to be “downloaded” into the brain.

“A good night's sleep within 30 hours of trying to remember a new task is a necessary condition of having good recall in the weeks ahead，” scientists have found.

“We think that getting that first night's sleep starts the process of memory consolidation(加强)，” said Robert Stickgold, a sleep researcher at Harvard Medical School who conducted the latest study.

“It seems that memories are normally washed out of the brain unless some process nails them down. I feel uncertain that sleep is one of those things that do the nailing down，” Professor Stickgold said.

Professor Stickgold's team trained the 24 people to tell the direction of three diagonal bars (斜线) shown for a sixtieth of a second on a computer screen full of horizontal stripes(水平线)．

Half the subjects were kept awake that night, while the others slept. Both groups were allowed to sleep for the second and third nights to make up for any differences in tiredness between the volunteers.

Those who slept the first night were much better at remembering the task while the second group showed no improvement in spite of enjoying two nights of catch－up sleep.

A further study by scientists at the Medical University at Lubeck in Germany showed that memories are laid down in two stages during the night. The first is during the deep, so－called “slow wave” sleep, which usually takes place in the first half of the night. The second, and less important stage happens during the periods of dreaming or “rapid eye movement (REM)”. When people don't sleep well in the first half of the night, their memory consolidation is almost the same as having no sleep at all.

1. Which of the following statements is CORRECT according to the first paragraph?

A. It is necessary to burn the midnight oil before an exam or interview.

B. Sleep speeds up the loss of memory.

C. Man should have a good sleep if he wants to keep a good memory.

D. Staying up late will make you better prepared for an exam or interview.

2. It can be inferred from the fourth paragraph that________.

A. some process helps memories to be washed out of the brain

B. Professor Stickgold is doubtful about whether sleep can make memories worse

C. some memories normally influence the function of the brain

D. sleep may can improve the condition of memories

3. How was the research conducted by Professor Stickgold?

A. The subjects were divided into two groups.

B. All the subjects were kept awake for 3 nights.

C. One group slept at the first night but was kept awake the next two nights.

D. One group was kept awake for 3 nights but the other slept for the second and third nights.

4. What was the study result of the scientists' at the Medical University at Lubeck?

A. REM sleep is not important at all for the consolidation for memory.

B. Intellectual performance mainly depends on the slow wave sleep period.

C. When people sleep poorly in the first half of the night, it is almost the same as having no sleep at all.

D. REM sleep is as important as slow wave sleep in terms of memory recall.

5. The BEST title of this passage is “________”．

A. Sleep Necessary for Memories

B. The Importance of the First Stage of Sleep

C. Studies Made by Scientists About Sleep

D. The Scientists' Achievement in Sleep Research

All the photographs in this book, _______ stated otherwise, date from the 1970s.

Some people argue using _______ nature to meet our own needs may spell disaster, unless we start to look around and understand how _________ clean environment benefits us all.