阅读下面的短文,文中有15处空白,每处空白给出了4个选项,请根据短文的内容从4个选项中选择1个最佳答案。
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7 N; I, Q/ V! d& M" ^$ S A Biological Clock % Q4 \' w! b/ i* P
Every living thing has what scientists call a biological clock that controls behavior. The biological clock tells _____1___ when to form flowers and when the flowers should open1. It tells _____2____ when to leave the protective cocoon and fly away, and it tells animals and human beings when to eat, sleep and wake.
2 [0 f0 S. A+ T Events outside the plant and animal _____3_____ the actions of some biological clocks. Scientists recently found, for example, that a tiny animal changes the color of its fur ____4_____ the number of hours of daylight. In the short ____5___ of winter, its fur becomes white. The fur becomes gray brown in color in the longer hours of daylight summer. " u# I3 i, v# i. G) L
Inner signals control other biological clocks. German scientists found that some kind of internal clock seems to order birds to begin their long migration _____6____ twice each year. Birds _____7_____ flying become restless when it is time for the trip, ____8___ they become calm again when the time of the flight has ended.
/ N5 D# r0 I4 g$ G Scientists say they are beginning to learn which ____9____ of the brain contain biological clocks. An American researcher, Martin Moorhead, said a small group of cells near the front of the brain ____10____ to control the timing of some of our actions. These ____11____ tell a person when to _____12_____, when to sleep and when to seek food. Scientists say there probably are other biological clock cells that control other body activities. & g' V) b+ v4 d$ _+ a9 a
Dr. Moorhead is studying _____13____ our biological clocks affect the way we do our work2. For example, most of us have great difficulty if we must often change to different work hours. _____14____ can take3 many days for a human body to accept the major change in work hours. Dr. Moorhead said industrial officials should have a better understanding of biological clocks and how they affect workers. He said ____15____ understanding could cut sickness and accidents at work and would help increase a factory’s production. ; B2 G! ~* g- r6 P
1. A scientists B humans C plants D animals " g" _4 J: R( ] Q: M4 s
2. A insects B birds C fish D snakes 来自www.Examw.com8 B' l/ y2 v1 E2 E
3. A effect B affect C effected D affected , h, u( k; l/ g& [
4. A because B for the reason that C because of D since
" i8 A4 M! |' W Z O( U+ w3 w 5. A months B days C minutes D weeks
/ P: s i- A9 y! f* f9 J4 A 6. A flight B fly C movement D transportation
. j( j0 ?, b# H 7. A prevented from B ordered by C helped by D intruded on ; P( ~8 F5 W7 I; D
8. A and B but C therefore D however
7 r5 N+ @, J W; p 9. A portions B parts C sections D kinds 9 P5 P# o; k# I; |4 ^; o' c
10. A try B tries C seem D seems ; ^# p' M% M% C
11. A things B parts C cells D actions ! F/ U1 L' j" G3 Z# B
12. A awaken B wake C awakening D wake-up # o8 K& N& n% d5 a% X7 i' {( i# J6 I
13. A how B why C where D what
8 S6 Q' `" R1 }: R$ { 14. A We B It C They D You
. f& F3 M9 ^5 q, T" K+ b 15. A so B with C such D if
+ a+ X! O: u) ]: n! c# b8 N 答案:CABCB AABBD CAABC |