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。 - V) g9 y# h' t8 c) v
; }8 G9 M: z# J0 G; M% c A Biological Clock
4 U: |& M- Y: U0 D ^* R/ E 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. . v8 r, j- S( n5 W
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. 3 }: O" `1 R2 j! t y
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. " e! F+ L6 Y( Y# n2 M3 L, j
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.
% D8 ?) |; [5 A" Z! [( Z 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. # E+ \4 k# N- ]6 ]% e9 J
1. A scientists B humans C plants D animals
3 Y/ K& C. }% b! A 2. A insects B birds C fish D snakes 来自www.Examw.com
9 |6 g6 T6 H9 F i 3. A effect B affect C effected D affected + p" Y, v D) J/ m3 I0 K' e
4. A because B for the reason that C because of D since
; R2 e) _+ k! j2 L# c, ~ 5. A months B days C minutes D weeks 3 {! _5 q E) W% Q$ h7 u& `
6. A flight B fly C movement D transportation - R. ~6 i, T& i
7. A prevented from B ordered by C helped by D intruded on 0 Z. U2 r4 G5 v6 r
8. A and B but C therefore D however . A: Z0 r2 m' H+ Q
9. A portions B parts C sections D kinds
: C, N. B6 Q. @: d! H1 }/ E/ O 10. A try B tries C seem D seems 0 P: P% o$ {+ O' Z) l! A8 g
11. A things B parts C cells D actions / u7 P% c8 |/ C& w4 A& _2 {; j8 w: m* ?
12. A awaken B wake C awakening D wake-up % @8 J" a$ {4 \+ p W3 U8 @' S% g
13. A how B why C where D what
7 ^# k) r5 x. T8 k2 ^& M* y7 i 14. A We B It C They D You
: n; c$ k7 n" W 15. A so B with C such D if
1 Z/ V+ B& L1 K+ Y1 n2 @ 答案:CABCB AABBD CAABC |