At the beginning of this century, medical scientists made an interesting discovery: we are built not just of flesh(肌肉) and blood but also of time. They were 21 to show that we all have a ‘body clock’ 22 us, which controls the 23 and fall of our body energies, 24 us different from one day to the next.
The 25 of a ‘body clock’ should not be too 26 since the lives of most living things are controlled 27 the 24-hour night-and-day cycle(循环). We feel 28 and fall asleep at night and become 29 and energetic during the day. If the 24-hour cycle is 30 most people experience unpleasant 31 . For example, people who are not 32 to working at night can find that 33 of sleep causes them to 34 badly at work.
35 the daily cycle of sleeping and 36 , we also have other cycles which 37 longer than one day. Most of us would 38 that we feel good on some days and not so good on 39 ; sometimes our ideas seem to flow and at other times, they 40 do not exist.
1.
A. anxious B. careful C. able D. proud
2.
A. around B. inside C. between D. on
3.
A. rise B. supply C. use D. movement
4.
A. showing B. treating C. changing D. making
5.
A. idea B. opinion C. story D. invention
6.
A. difficult B. exciting C. interesting D. surprising
7.
A. from B. over C. by D. during
8.
A. dull B. dreamy C. tired D. peaceful
9.
A. regular B. excited C. clear D. lively
10.
A. shortened B. disturbed C. reset D. troubled
11.
A. moments B. senses C. feelings D. effects
12.
A. used B. allowed C. expected D. prevented
13.
A. miss B. none C. need D. lack
14.
A. show B. perform C. manage D. control
15.
A. With B. Except C. As well as D. Rather than
16.
A. waking B. moving C. living D. working
17.
A. repeat B. remain C. happen D. last
18.
A. believe B. agree C. realize D. allow
19.
A. others B. the other C. all other D. other
20.
A. only B. just C. still D. yet
---I’m afraid that Mr. Wood can’t see you until 4 o’clock.
---Oh, ______ I won’t wait.
A. no doubt B. after all
C. in that case D. in this way
. Little ______ about her own safety, though she was in great danger herself.
A. did Rose care B. Rose did care
C. Rose does care D. does Rose care
______ to reach them on the phone, we sent an email instead.
A. Fail B. Failed
C. To fail D. Having failed
Our bodies are strengthened by taking exercise. ______, our minds are developed by learning.
A. Probably B. Likely C. Similarly D. Generally
American Indians ______ about five percent of the U.S. population.
A. fill up B. bring up
C. set up D. make up
