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
小学英语游戏 猜谜语
少儿英语课堂游戏:抢凳子
英语课堂游戏:反义词拔河赛
游戏学英语 谜语和脑筋急转弯问题集锦1
集中识词中的游戏运用
小学英语游戏
少儿英语游戏:四月的云彩 April Clouds
英语游戏 看卡通,学英文字母
英语单词游戏 蜗牛学英语
游戏学英语 谜语和脑筋急转弯问题集锦2
英语游戏 人教版小学五年级英语上册3
小学英语游戏 超级粉刷匠
英语谜语11则
儿童英语游戏 不会飞行的鸟Birds that Can’t Fly
小学英语游戏 魔法拼写
英语课堂游戏:排队造句
儿童英语flash游戏 大画家
小学英语课堂游戏:将错就错
小学英语交通工具涂色
小学英语游戏 叠汉堡
小学英语游戏:what colour……
英语听力游戏:此呼彼应
小学英语单词游戏:换宝
玩游戏学英语 猜谜语(附答案)
英语游戏 人教版小学五年级英语上册5
小学英语游戏 打字狙击手
少儿英语游戏:电话游戏
小学英语游戏 汽车维修工
少儿英语游戏:五只小猴子 Five Little Monkeys
游戏学英语 脑筋急转弯
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |