1. whether　 2. whether　　 3. what　　 4.whoever　　 5. whatever　　 6. whichever　 7.where　　 8. why　　　 9.which　　 10.what　　 11. whoever　　 12. how　　 13. that　

20.　 It looks ________ it were going to rain.　

Keys:

19.　 This is ________ we overcome the difficulties.　

18.　 The little boy can’t tell ________ his home is.　

17.　 Do you know ________ shall we meet?　

16.　 I am not sure ________ he can pass the exam or not.　

15.　 The shopkeeper did not want to sell for ______ he thought was not enough.

14.　 The reason was _______ Tod had never seen the million-pound note before.

13.　 I know ________ Henry must be worried about what will happen to him.

12.　 I can’t tell you ________ I would feel if you gave me a million yuan.