4.　　　 Those small coal factories are causing a lot of e_____ pollution with all their dust.

3.　　　 The young man from abroad is in charge of the d_______ of biology of Beijing University.

2.　　　 His manner made it clear that he wasn’t a common gunman, but a p_______.

1.　　　 Nowadays our world faces three big problems; development, peace and p_________.

25.　 In our ________ lessons we study Shakespare’ plays and stories by Dickens.

24.　 The new buildings have changed the _______　 of the town.

23.　 I must say I think it is a _______　 way of killing time .

22.　 It is a good ________　 to go for a walk after supper.

21.　 She looked ________ after she read the letter.

20.　 The engineer felt that he hadn’t been t______ fairly.