这是形式主语it还是there be句型

下面这道题是考查形式主语it还是there be句型?

Have __________ been any changes in your home town?

A. it                        B. you              C. that                        D. there

此题应选D。容易误选A，误认为这里应填形式主语。

其实考生只要想一想，假若选A，it是形式主语，那么请问此句真正的主语是什么? (找不到!)

正确的分析：此句为there be-句型，这里要特别注意的是：there be-结构不仅可以有各种时态，而且还可以与情态动词以及 happen, appear, seem 等动词连用。本题用的就是there be-句型的现在完成时态的一般疑问句形式。

以下各句用的是否是 there be-句型，你看得出来吗?

1. There is going to _________ an English film the day after tomorrow.

A. have                   B. be                      C. do                        D. see

2. _________ have been many such accidents here.

A. It                       B. There                 C. They                    D. We

3. ________ used to be a big tree in front of the old house.

A. It                       B. There                 C. They                    D. That

4. There must have _________ something wrong with the machine.

A. been                   B. gone                  C. had                       D. done

5. _________ happened to be a foreign teacher there.

A. It                       B. There                 C. They                    D. That

6. There seems to __________ a storm soon.

A. have                   B. be                      C. fall                       D. blow

答案：1. B 2. B 3. B 4. A 5. B 6. B