there 还是 it
请看下面这道题：
_________ doesn’t seem to have been much difficulty in solving the problem.
A. It B. That C. There D. He
许多同学一看选项便想当然地认为，这是考查形式主语 it 的用法，所以便毫不犹豫地选了A。同学们仔细想想看，假若此题选形式主语 it，那么真正的主语在哪儿呢？没有。其实，此题应选C，属 there be 句型一种比较复杂的表现形式，请看下面几个句子，它们均属there be 句型，但结构一个比一个复杂：
There is much difficulty in solving the problem.
There seems to be much difficulty in solving the problem.
There seems to have been much difficulty in solving the problem.
There doesn’t seem to have been much difficulty in solving the problem.
以下各句用的是否是 there be句型，你看得出来吗?（答案均选B）
(1) There is going to _________ a class meeting tonight
A. have B. be C. do D. attend
(2) _________ used to be a big tree in front of the old house.
A. It B. There C. They D. That
(3) _________ happened to be a foreign teacher there.
A. It B. There C. They D. That
(4) There seems to _________ a storm soon.
A. have B. be C. fall D. blow
(5) _________ have been many such accidents here recently.
A. It B. There C. They D. We
(6) There must have _________ something wrong with the machine.
A. gone B. been C. had D. done
(7) _________ is said to be no life on the moon.
A. It B. There C. That D. He