Question

英语高手进,帮我分析下

⒈.No sooner__ finished the joke than everyone burst out laughting.
A. had he B. has he
答案是A,我不知道为什么啊,后面不是一般现在时么,前面应该是现在完成时啊, 我记得书上是这样写的,如果后面是过去时,前面才用现在完成时..

还有一道
⒉He tried to concentrate,____he found difficult, as people were telling each other funny jokes outside.
A.what B. which
答案是B,为什么不是what呢,不是指前面的Concentrate么???

⒊If the bus ___at 7 , What would you do ?
A.would not come B. were not come C. will not come D had not come
答案是B
这个IF引导是真实还是非真实? 是与现在事实相反么?为什么不是C???

⒋It's highly important that he ___at the meeting on time tomorrow.
A is B was C be D being
答案是C,想知道为什么?

⒌He ___before I had time to tell him my name.
A.hanged up B.hung up
答案是B 为什么不是过去式呢,在我告诉他我名字之前呀/

I wish he ___me before he took part in that contest.
A had told B has told C told D would have told
答案是A ,我选的是D,不是与过去相反么?

谢谢啦,
我没有分
但是懂的人帮我仔细分析下吧,

Answer 1

1. 后面用的是一般过去时，从burst体现出来的，如果是一般现在时，那么burst应该换成bursts,因为主语是everyone
2. 考察Which引导的非限制性定语从句，which 指代前面整个句子。
3.考察虚拟语气。P.S.答案B也怪怪的，应该是were not to come吧
4.be前省略了should。
句型：It is highly important +that+主语+should+动词原形
5.hang作为“挂掉（电话）”讲时，过去式是hung
作为“绞死”讲时，过去式是hanged.
6.would have done 通常表示推测，“应该...”，并非与过去相反

Answer 2

先回答你的第一个问题：如果在一个句子中，两个动作都发生在过去，那么最早的要用过去完成时。其实都用过去时也不为错