课后练习：

1. Her mood is also darker, especially when she ________in the morning; it takes all her energy just to drag herself out of bed.

A. awakensB. awake C. wakeD. waken

2. Joseph, ________engineer for a Midwestern computer company, feels cranky early in the morning.

A. a 48-year-oldB. a 48-years-oldC. 48-year-old

3. The peaking of body temperature, ________occurs in most people every evening, is a daily rhythm.

A. whichB. thatC. soD. while

4. The increase in sexual drive in the autumn—not in the spring, as poets would ________ —is a seasonal, or yearly rhythm.

A. have us believeB. have us to believeC. has us believe

5. The idea that our bodies are in ________ flux is fairly new—and goes________ traditional medical training.

A. constant; againstB. contract; against

C. content; againstD. constant; into

5. As early as ________, however, some scientists questioned the homeostatic view of the body.

A. the 1940sB. the 1940C. a 1940s

6. For example, the time of day ________a person receives X-ray or drug treatment for cancer can affect treatment benefits and ultimately mean the difference between life and death.

A. thatB. whenC. whichD. where

7. Gradually ________ had been considered a minor science just a few years ago is being studied in major universities and medical centers around the world.

A. where B. whatC. whoD. that

8. There are even chronobiologists ________ the National Aeronautics and Space Administration, ________ for the National Institutes of Health and other government laboratories.

A. work for; as well asB. working for; as well as

C. working for; as early asD. working; as well as

9. With their new findings, they are teaching us things that can literally change our lives, so we can ________our natural rhythms________against them.

A. work for; rather thanB. work with; rather than

C. work with; ratherD. work to; rather than

10. How you feel, how well you work, your level of alertness, your sensitivity to taste and smell, the degree with ________you enjoy food or take pleasure________ music—all are changing throughout the day.

A. which; ofB. which; inC. that; in（that前不有用介词）

11. Your short-term memory is best during the morning—in fact, about 15 percent more efficient than ________.

A. at any time of day B. at other time of day

C. at any other time of day

12. Late in the day, when your body temperature is peaking, you will perceive a physical workout to be ________ and________.

A. easy; less fatiguingB. easier; fatiguing

C. easier; less fatiguing

13. That could be ________dinner usually tastes better to us than breakfast and ________night lights irritate us.

A. that; thatB. what; whatC. why; why

14. Not only ________time seem to fly when you're having fun, ________it also seems to fly even fester if you are having that fun in the late afternoon and early evening, when your body temperature is also peaking.

A. does; andB. do; butC. does; but

15. Learn how to listen to the inner beats of your body; let them ________the pace of your day.

A. settingB. to setC. Set

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