20.　 比较级

　 The population of Japan is 126.5 million . The population of Britain is 59.5 million.

= The population of Japan is larger than that of Britain.　 (*单数that/复数those)

19.　 in a flash =in a blink of an eye

18.　 be absent from 　ant.　 　be present at

17.　 return to = go back to

16.　 hardly ever　 = almost never

15.　 send in = hand in = submit

14.　 mustn’t do sth = sb be not allowed to do sth

13.　 not only A but also B = B as well as A

12.　 accidentally = by accident

11.　 It’s time (for you) to go to bed. = It’s time for bed.