A. The enemy should be allowed
B. Should the enemy be allowed
C. Should allow the enemy
D. The enemy should allow
2. The party has always had a cautious and＿＿attitude to Europe.
3. It will be casting pearls before＿＿because he does not know how to appreciate favors.
4. To be frank, I’d sooner you＿＿a good review yesterday for the coming test.
A. Hadn’t done
B. Didn’t do
C. Couldn’t have done
D. Wouldn’t do
5. He said it would not be all that difficult to reach a peaceful conclusion to the＿＿.
1. 【B】倒装结构题。本句中有带有否定意义的短语under no circumstances，表示“在任何情况下都不”，其主谓部分要倒装，所以应选B。C中缺少宾语从句中的主语。
2. 【C】obedient: doing what one is told to do; willing to obey
Overwhelming: having such a great effect on you that you feel confused and do not know how to react
Skeptical: tending to disagree with what other people tell you
Subsidiary: connected to but smaller, of less importance,etc than sth else; subordinate
3. 【B】cast pearls before swine 是固定搭配，表示“对牛弹琴”。Swine表示“猪”。
4. 【A】would sooner表示“宁愿”，后接宾语从句时应用虚拟语气，本句宾语从句中是对过去事实的虚拟，所以应用过去完成时。
5. 【D】paradox: statement that seems to be absurd or contradictory but is or may be true
Dilemma: situation in which one has to choose between two undesirable things or courses of action
Prejudice: opinion, or like or dislike of sb/sth, that is not founded on experience or reason
Conflict: serious disagreement; argument; controversy