23.Theis is one of the most interesting questions that ____ asked.

A.have　　　　　　 B.has　　　　　　 C. have been　　　 D.has been

22.He is the only one of die students who ____ elected.

A. are　　　　　　 B.have　　　　　 C.has　　　　　　 D.is

21.The United States of America　　　 one of the most developed countries in the world.

A.is　　　　　　 B.are　　　　　 C.was　　　　　 D.were

20. The Olympic Games ____ held every ____ years.

A.is;four　　　　　 B.are;four　　　　 C.is;five　　　　　 D.are;five

19. A chemical works____ built there.

A. is to being　　　　 B.have been　　　 C. were to　　　　　 D.has been

18. Chairman Mao' s works ____ published.

A. has been　　　　　 B.have been　　　 C.was　　　　　　 D.is

17. The Arabian Nights ____ well known to the English.

A. is　　　　　　　 B. are　　　　　　 C. was　　　　　 D. were

16. The number of deer, mountain lions and wild roses ____ much if people leave things as they are.

A. doesn' t change　　 B.don't change　　ge　　　　　ged

15. A large number of students in our class____ girls.

A. are　　　　　　　 B. was　　　　　　 C. is　　　　　　　 D. be

14. There ____ a pen, two pencils and three books on the desk.

A.are　　　　　　　 B.is　　　　　　　 C.has　　　　　　 D.have