大学英语六级考试攻克语法必备练习(1)

　　大学英语六级考试攻克语法必备练习

　　1.So many students get failed in the final examination.It is strange that such a thing __1__in your school.It is important that the results of an experiment__2___.

　　1. happens happened

　　should happen had happened

　　2.check and recheck checking and rechecking

　　be checked and rechecked checked and rechecked

　　2.The people who knew him very well said that he was too na ve sometimes.Had he been older,he___1___less sympathetic.But what he had done proved that he was the person,loving life,also a hero who can help others out of trouble.___2___his timely arrival, the boy would have been drowned.That gained respects for him.

　　3.might have been would be

　　might be had been

　　4.But for Even for

　　Except for If not

　　1. 选该题考察表示惊奇、高兴、遗憾、担心等感情色彩的形容词引起的主语从句中的虚拟语气的表达。在 anxious,sorry,concerned,happy,delighted等表示感情色彩的形容词后接的that 从句中，用should来修饰谓语动词。该句中有strange一次，意为奇怪，表示对事物的惊讶或不满，it为形式主语，that从句为主语从句，要求从句中用虚拟语气的表达形式should+动词原形表示

　　2. 选该题考察its+adj.+that主语从句的虚拟形式。观察句子结构可以看出这里为Its+形容词+that从句结构，形容词important做表语，主语从句需要虚拟形式should+动词原形，should可以省略

　　3. 选该题考察非真实条件的虚拟。在表示过去情况的虚拟条件句中，条件从句用了过去完成时形式，主句可用should+have+过去分词的形式

　　4. 选该题考察含蓄条件的虚拟。But for含义为要不是，用于此处可以表达假设条件，but for his timely arrival=If it had not been for his timely arrival或If he had not arrived on time.