Flood,（)and famine are natural disasters often facing the people in the peninsula. A: A.war B: B.sanction C: C.overpopulation D: D.drought

Bendable screen and human overpopulation are all related to the environment change.

Which of the followingis not the main cause of water scarcity? A: war B: water contamination C: overpopulation D: climate change

According to the passage, if we go on increasing the population, we will face （）. A: a food shortage B: a crisis C: an overpopulation D: a starvation

Air pollution, together with overpopulation, _______many problems in big cities today. A: are causing B: is causing C: are caused D: is caused

中国大学MOOC: Overpopulation poses a terrible threat to the human race. Yet it is probably ________a threat to the human race than environmental destruction.

Overpopulation poses a terrible threat to the human race. Yet it is probably ________a threat A: the human race than environmental destruction. （07年真题） B: no more C: not more D: even more E: much more

It can be inferred from the passage that _________. A: higher agricultural production can solve the problem of overpopulation B: obtaining enough funds is important to introduce new industries C: modern and advanced techniques need more farmers on land D: nowadays it is secure for developing countries to rely on the external support

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