Question

  Some people are night owls. Some are early birds. You almost certainly know w   (1) one you are. But did you know that there may be a biological r   (2) why some people are out of bed so early in the morning w (3) others prefer to stay up late at night?

  One German scientist believes that people's body clocks are s (4) by their genes,and cannot be c (5) That means some people will r (6)their physical peak(生理巅峰)later in the day than o (7) If they are forced to work a (8)their own clocks,they are unlikely to be able to do their b (9)This could even lead to health p (10) for them.

  The scientist thinks that people who need to stay in bed longer in the morning should not be looked on as lazybones because their genes are making them do so.

1. w     2. r         3. w         4. s     5. c       

6. r       7. o     8. a        9. b       10. p       

Answer 1

1. which 2. reason 3. while 4. set 5. changed 

6. reach 7. others 8. against 9. best 10. problems