It is our wish that she______what she likes. A: take B: B．takes C: C．will take D: D．can take

The train 2515 __________at 8:00 every morning A: is leaving B: B.leaves C: C.will leave D: D.has left

— How soon _______ all the work ______? — In a week． A: A．will；finish B: B．is；going to finish C: C．will；be finished D: D．are；going to be finished

If anyone at work _______ my secret, I’ll lose my job． A: A.find out B: B.discovers C: C.will find D: D.will know

We（）here for twenty years by the end of next month. A: A.will live B: B.have lived C: C.will have lived D: D.will be living

It’s difficult to get to the other side of the river．I think a bridge _______ over the river． A: A．should be built B: B．should build C: C．will build D: D．has built

比较C≡C, C=C, C─C, C=C─C=C的键长次序为: C=C─C=C>C─C> C≡C >C=C|C=C─C=C>C─C>C=C>C≡C|C≡C>C=C>C─C>C=C─C=C|C─C>C=C>C=C─C=C>C≡C|C─C>C=C─C=C>C=C>C≡C

下列哪种主链骨架原子排列最能代表两个肽键?() A: Cα—N—Cα—C—Cα—N—Cα—C B: Cα—N—C—C—N—Cα C: C—N—Cα—Cα—C—N D: Cα—C—N—Cα—C—N E: Cα—Cα—C—N—Cα—Cα—C

比较C≡C(Ⅰ),C=C(Ⅱ),C─C(Ⅲ),C=C─C=C(Ⅳ)的键长次序为( )。 A: Ⅰ＞Ⅱ＞Ⅲ＞Ⅳ B: Ⅲ＞Ⅱ＞Ⅳ＞Ⅰ C: Ⅲ＞Ⅳ＞Ⅱ＞Ⅰ D: Ⅳ＞Ⅲ＞Ⅱ＞Ⅰ

不稳定的一类化合物是: C≡C|C－C|C＝C|C＝C－C＝C|C＝C＝C