2002年上海市普通高等学校春季招生考试英语试卷第36小题
It ____ long before we ____ the result of the experiment．
A．will not be；will know
B．is；will know
C．will not be；knowD．is；know
这是一道考查It will not be ＋时间段＋before从句句型的题，答案应为C。it句型是高考的重要句型，这就要求考生平时注意掌握好这种句型，把知识系统化，现就这道高考题归纳一下it句型。
1．It will be ＋时间段＋before从句
表示“过多久就会发生某事”；若主句中用will not be则表示“不长时间就会发生某事”；若主句中用was则表示“过了多久某人就干某事了”；若主句中用wasn't则表示“没过多久某人就干某事了”。例如：
①It will be an hour before you see Mr Li．
②It will not be long before he comes back．
③It was three weeks before they finished the work．
2．It is ＋时间段＋since从句
表示“自从……以来已有多长时间了”。指由过去某一时刻起到现在为止的一段时间的总和，从句多用一般过去时。例如：
①It is ten years since he came back．
②—What was the party like？
—Wonderful！It's years ____ I enjoyed myself so much．（MET93）
A．after B．before C．when D．since
3．It is up to sb．to do．．．
表示“该由某人负责做……”。例如：
①It is up to you to water these trees．
②Who is it up the firstcompany is run by the state？
A．to take charge of；which
B．to to take charge of；that
C．for to take charge of；that
D．to to taking charge of；which
4．It is（high）time＋that＋S．＋V．＋．．．
表示“该是某人做某事的时候了”，其中that从句的谓语动词常用过去式，表示与现在事实相反的虚拟语气。例如：
①It is high time that he went to work．
②It is time that you got down to doing your work．
5．It was ＋具体时间＋when＋S．＋V．＋．．．
表示“某事发生的时间是……”。例如：
①It was eleven o'clock sharp when the policemen arrived last night．
②It was five o'clock in the afternoon ____ they climbed up to the top of the mountain．（NMET96）
A．since B．when C．that D．until
6．Itisnowonder＋that＋S．＋V．＋．．．
表示“难怪某人……”、“……不足为奇”。例如：
①It is no wonder that he won't come．
②They are all classmates． ____is no wonder they should help each other with their studies．
A．This；whether B．It；if C．That；that D．It；that
7．It is＋adj．＋（for ／of sb．）＋todo．．．
表示“（某人）做某事是……”。若表示事物的特点或特征时，用for sb．；若表示人的特征或特点时，用ofsb．；若表示动作的特点时，常用不定式。例如：
① It is important for us to learn English．
②It is wise of you to make such a decision．
③Is ____ necessary to complete the design before National Day？（MET89）
A．this B．that C．it D．he
8．It is（was）the first time＋that＋S．＋V．＋．．．
表示“这是某人首次……”。主句中用is时，that从句的谓语动词常用现在完成时；主句中用was时，that从句的谓语动词常用过去完成时。例如：
①It is the first time that I have visited West Lake．
②It was the first time that she had worked in the company．
