2022年职称英语完形填空练习题综合类A级(7)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 open. 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.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 in 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 _6_ twice each year. Birds _7_ from flying become restless when it is time for the trip, _8_ they become calm again when the time of the flight has ended.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.Dr. Moorhead is studying _13_ our biological clocks affect the way we do our work. For example, most of us have great difficulty if we must often change to different work hours. _14_ can take 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.1. A) scientists B) humans C) plants D) animals2. A) insects B) birds C) fish D) snakes3. A) effect B) affect C) effected D) affected4. A) because B) for the reason that C) because of D) since5. A) months B) days C) minutes D) weeks6. A) flight B) fly C) movement D) transportation7. A) prevented from B) ordered by C) helped by D) intruded on8. A) and B) but C) therefore D) however9. A) portions B) parts C) sections D kinds10. A) try B) tries C) seem D) seems11. A) things B) parts C) cells D) actions12. A) awaken B) wake C) awake D) wake-up13. A) how B) why C) where D) what14. A) We B) It C) They D) You15. A) so B) with C) such D) ifKEYS: CABCB AABBD CAABC