22.____has passed the test will get a prize .

　 A. Whoever　　 B. No mater who　 C. Whomever　 D. Who

21. ____he always serves the people very well is known.

　 A. What　　 B. That　　 C. Which　 D. Who

20. ____caused the accident is still a complete mystery.

　 A. What　　 B. That　　 C. How　　 D. Where

19. It is widely ______that smoking can cause cancer.

　 A. believed　 B.　 think　　 C. say　　　　 D. hoped

18. ____appeared to me that he enjoyed the food very much.

　 A. What　　　 B. It　　　　 C. All that　　 D. That

17.____all the inventions have in common is ____they have succeeded.

　 A. What; what　 B. That; that　 C. what; that　 D. That ; what

16. ____you don’t like him is none of my business.

　 A. What　 B. That　　 C. Who　　 D. How

15.____he will go to work in a mountain village surprises all of us.

　 A. What　 B. That　 C. Whether　 D. If

14. ­­­_____more countries can use natural energy in the future remains to be seen.

　 A. Whether　 B. This　 C. who　 D. If

13. It worried her a bit _____her hair was turning gray.

　 A. while　 B. if　　 C. that　 D. for