A Biological Clock
Every living thing has what scientists call a biological clock that controls behavior. The biological clock tells ___C__1___ when to form flowers and when the flowers should open1. It tells ___A__2____ when to leave the protective cocoon and fly away, and it tells animals and human beings when to eat, sleep and wake.
Events outside the plant and animal ___B__3_____ the actions of some biological clocks. Scientists recently found, for example, that a tiny animal changes the color of its fur __C__4_____ the number of hours of daylight. In the short ____5__B_ of winter, its fur becomes white. The fur becomes gray brown in color in the longer hours of daylight summer.
Inner signals control other biological clocks. German scientists found that some kind of internal clock seems to order birds to begin their long migration ___A__6____ twice each year. Birds ____A_7_____ flying become restless when it is time for the trip, _B___8___ they become calm again when the time of the flight has ended.
Scientists say they are beginning to learn which __B__9____ of the brain contain biological clocks. An American researcher, Martin Moorhead, said a small group of cells near the front of the brain __D__10____ to control the timing of some of our actions. These ___C_11____ tell a person when to ___A__12_____, when to sleep and when to seek food. Scientists say there probably are other biological clock cells that control other body activities.
Dr. Moorhead is studying __A___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. ___B__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 __C__15____ understanding could cut sickness and accidents at work and would help increase a factorys production.
1. A) scientists B) humans C) plants D) animals
2. A) insects B) birds C) fish D) snakes
3. A) effect B) affect C) effected D) affected
4. A) because B) for the reason that C) because of D) since
5. A) months B) days C) minutes D) weeks
6. A) flight B) fly C) movement D) transportation
7. A) prevented from B) ordered by C) helped by D) intruded on
8. A) and B) but C) therefore D) however
9. A) portions B) parts C) sections D) kinds
10. A) try B) tries C) seem D) seems
11. A) things B) parts C) cells D) actions
12. A) awaken B) wake C) awakening D) wake-up
13. A) how B) why C) where D) what
14. A) We B) It C) They D) You
15. A) so B) with C) such D) if
考研英语作文写作小技巧讲解
2015考研英语大作文真题答案预告
2015考研英语作文冲刺:大作文预测及范文
2015考研英语一小作文真题范文(新东方版)
2015考研英语二作文终极预测
2015考研英语作文预测:“互信”
2015考研英语一小作文真题(文字版)
2015考研英语小作文真题答案预告
2015考研英语一作文终极预测
2015考研英语二大作文真题范文(新东方版)
2015考研英语二小作文真题答案预告
2015考研英语二小作文真题预告
2015考研英语小作文真题预告
2015考研英语一大作文真题(文字版)
2015考研英语二大作文真题答案(新东方版)
2014年考研英语作文及范文
2015考研英语作文高分冲刺:4招征服阅卷老师
2015考研英语二小作文真题(图片版)
2015考研英语二大作文真题答案预告
考研英语历年作文题及范文汇总(1991-2014)
2015考研英语二写作真题完整版
2015考研英语作文话题预测:文化与教育及范文
2015考研英语二小作文真题解析及范文
2015考研英语二大小作文真题(图片版)
2015考研英语二大作文真题解析及范文
2015考研英语小作文:高分非难事
2015考研英语作文冲刺:四步骤确定考研作文模板
2015考研英语一写作真题答案完整版
2015考研英语写作真题答案预告
2015年考研英语作文题目预测
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |