9. ____ four years since I joined the Army.

       A. There was         B. There is             C. It was               D. It is

8. The climate of Shanghai is better than ____ of Nanjing.

       A. that                  B. it                      C. which               D. what

7. We think ____ our duty to pay taxes to our government.

       A. that                  B. this                   C. its                     D. it

6. ____ will do you good to do some exercise every morning.

       A. It                            B. There                C. Those                D. You

5. The color of my coat is different from ____ of yours.

       A. this                   B. that                   C. it                      D. one

4. ---- Have you ever seen a whale alive?            ---- Yes, I've seen ____.

       A. that                  B. it                      C. such                  D. one

3. ____ was Jane that I saw in the library this morning.

       A. It                            B. He                    C. She                   D. That

2. ---- Who's that?                ---- ____ Professor Li.

       A. That's              B. It's                    C. He's                  D. This's

1. My bike is missing. I can't find ____ anywhere.

       A. one                   B. ones                  C. it                      D. that

10．It is (high) time that sb． did sth．

该句型表示"某人现在该做某事了"，从句常用过去时（虚拟语气）

说明现在应该做的事情。如：

It's six o'clock．It is high time that we went home now．

练习.It的用法