Question

英语现在完成时与过去完成时题型，最好有讲解！谢啦！

Jack and Susan __ each other since they were children ,so nobady was surprised to hear that they were married.

A.knew B.had known C.have know D.were known

Answer 1

B
这位同学，这个题比较明显的是since，然后主句就要用现在完成时。但是问题是答案里面没有符合条件的现在完成时，正确答案应为have known,所以我们就可以考虑过去完成时，因为它表示在过去已经完成了的动作，也就是说在他们还是孩子的时候，他们彼此已经认识了。

Answer 2

答案选 C.have know
since 一般和现在完成时连用， 由于下文 so nobody was surprised to hear that they were married.是一般过去时， 可见是相对这一过去时点来说的， 过去的过去， 用过去完成时

Answer 3

答案应该为have known

since 引到的从句一般用一般过去时，而主句则用现在完成时。

Answer 4

Since出现基本一定是完成时
如果C选项是have known, 则选B 和 C
如果就是题目那样，则只能选B

Answer 5

答案好像都不对啊