20. -How do you like a birthday party outdoors this weekend?　　 -_______.

A. Very much　 　　　　 B. With pleasure　 C. Have fun　　　　　 　　 D. Good idea

19. The earthquake in Japan, measuring 9.0 on the Richter Scale, was so violent _________ cause a series of explosions of the nuclear reactors in several power stations.

A. to　 　　　　　　　　　　 B. that　　 　 　　　　　 C. as to 　　　　　　　　　　　 D. as that

18. China made a promise to the world in the Copenhagen Summit that by 2020, the carbon-intensity of its economy ______ fall 40% to 45%.

A.　shall　　　　　 　 B. may　　　　　 C. must　　　　　 　　　　 D. should

17. You have failed again! Were I you, I _______it the first time.

A. passed　 　　　　　　　 B. would pass　 　　 C. would have passed　　 D. had passed

16. -Have you received any phone calls from your sister?

-Not yet, but we _______ to get in touch with her ever since she left us.

A. have tried　 　　　　　 B. tried　 　　　　　　　　　　 C. are trying　　　　　　　　 D. have been trying