It 常见的四个句型It seemed only several minutes ________ he made up his mind and told us his decision.A.thatB.sinceC.whenD.before记住四个句型，能帮助你又快又正确做这样的题。
1. It was +时间点+ when sth. happened. 表示：当某件事发生时，时间（it)是。
如：It was 1997 when Hongkong returned to China.2. It was +时间段+before sth. happened. 此句型前必有前文，表示在那件事发生之后，另一件事发生之前，这两点之间的时间是多长。
如接上句：It was two years before Macao returned to China too. 过了两年，澳门也回归了。
注：这个句型有两种情况，两种译法：2 a. It was a long time before sth. happened. 过了很久，才发生另一件事。
2 b. it wasn't long before sth. happened. 没过多久，另一件事也发生了。
3. It is( = has been) +时间段+ since sth. happened. 意为：自从过去某件事发生以来，到现在已经有一段时间了。
如：It is (=has been) 13 years since Hongkong returned to China.4. 强调句型：It was +被强调的部分+that+剩余部分。
举一个与例一很近的例子：It was in 1997 that Hongkong returned to China.原句为：Hongkong returned to China in 1997. 强调状语in 1997.本题只不过将系动词was改成了seemed, 属于2b句型。
译：好象没过几分钟他就下定了决心，并告诉了我们他的决定。
另注：这个句型还有将来时态：It will be some time before sth. happens. 要过多久才会发生某事。
It won't be long before sth. happens.不用过多久就会发生某事。
He was about halfway through his meal_______a familiar voice came to his ears．A．why B．where C．when D．while解析：答案是C。
此处when作并列连词，表示“就在此刻(and just then)”，“突然(and suddenly)”，由此借以引出追叙的事项。
该句译为：“饭刚吃到一半儿的时候，熟悉的声音传到了他的耳朵里。
”在中学英语中，我们经常见到与并列连词when相关的句式，现将其归纳如下：1．be (just) about to do... when...She was just about to say something more when she noticed the sullen look on his face．她刚要再说些什么，却突然看到了他阴沉的脸色。
We were about to telephone you when your telegram arrived．我们正准备给你打电话，这时你的电报来了。
2．be (just) on the point of doing sth．.. when．．．They were on the point of giving up when the captain encouraged them fiercely to save the ship．就在他们快要放弃努力时，船长鼓励他们竭尽全力挽救轮船。
The coach was just on the point of giving up the game when our team scored two points．教练正准备放弃比赛，这时我们队得了两分。
3．be going to do．．．when．．．He was going to run away，when the policemen came．他正打算逃跑，警察突然出现了。
She was going to open the window and shout at the dog to frighten it，when she stopped and stood quite still．她正准备打开窗户，大声吓唬一下那条狗，这时她突然停住了，站着一动也不动。
4．be doing sth ．．．when．．．The children are playing football on the playground，when it began to rain．孩子们正在操场上踢足球，突然下起了大雨。
A few days later，I was moving forward over a slope that seemed safe when suddenly without warning my world dropped out from under my skis．(必修本SEFC Book 1 Unit 17) 几天以后，我正在一个似乎安全的斜坡上前行，突然，毫无预兆，滑雪板下的大地陷下去了。
5．be busy doing.．．when．．．I was busy doing my homework when one of my classmates came．我正忙着做作业，这时我的一个同学来找我。
I was busy cooking when there was a knock at the door．我正在忙着做饭，突然听到了敲门的声音。
6．had （just) done．.．when．．．I had just gone to bed after a very hard day when the phone rang．在劳累了一天之后，我刚要上床睡觉，这时电话响了。
I had travelled only two hours one day when the winds increased so much that I had to put my tent up before the winds became too strong．(必修本SEFC Book 1 Unit17) 一天，我刚走了两个小时，突然狂风大作，我只好趁风力还不算太大之前，支起帐篷。
7．had not done．.．when．.．I hadn’t walked a few steps when I realized that he asked for the direc-tion to my office building．我还没走出去几步远，突然意识到他问的是去办公大楼的方向。
The students hadn’t played basketball long when the bell rang．学生们没玩多长时间篮球，铃就响了。
8．be + 介词短语+ when．．．He was on his way to a lecture when a tourist stopped him and asked him for directions．在他去听课的路上，一名游客拦住他问路。
The mother and the seven-year-old were inside the house when the shooting occurred．这位母亲和她7岁的孩子正在家里的时候，发生了枪击事件。
练习：1．I has just stepped out of the bathroom and was busily drying myself with a towel I heard the steps. (2006年湖南卷)A．while B．when C．since D．after2．I was still sleeping when the fire ，and then it spread quickly.(2006年广东卷)A．broke out B．put out C．came out D．got out3．I_______along the street looking for a place to park when the accident_______（2006年安徽卷）A．went; was occurring B．went; occurredC．was going; occurred D．was going; had occurred4．We were swimming in the lake suddenly the storm started.(2004年春季北京卷)A．when B．while C．until D．before5．Jasmine was holidaying with her family in a wildlife park_______she was bitten on the leg by a lion.(2004年上海卷)A．when B．while C．since D．once6．He was about to tell me the secret_______someone patted him on the shoulder.(2002年上海卷)A．as B．until C．while D．when参考答案：1．B2．A3．C4．A5．A6．D1.How long表示“时间多久或物体多长”. 表示时间侧重指“一段时间”.针对“How long” 的回答一般是时间段,如“for three days”, “three years”e.g. “How long were you away last year?”“About two weeks”3. How often表示“多少时间一次或每隔多久”.是就做某事的频率提问。
针对How often的回答一般是“Twice a year”. “Three times a week”.e.g. “How often do you watch TV?”“Tree times a week.”3. How soon表示“多久之后”.侧重某人某事能多快时间完成. How soon的回答一般为: “ in + 时间段” e.g. “ in two days” “in five years”e.g. “How soon will you be ready?”“I’ll be ready in five minutes”4．How far表示“多远”How far is it?[巩固练习]1. I don’t know_______ he will get here.A. how longB. how soonC. how oftenD. how many answer B2. “_____does he take this medicine?”“Twice a day.”A. How soonB. How longC. How muchD. How often answer D3. “_______have you been at this factory?”“I have been here since 1993.”A. WhenB. How longC. How oftenD. What time answer B4. “________can you finish this work?”A. How oftenB. How soonC. How longD. How far answer B5. “__________ will he stay here?”A. How many timesB. How oftenC. what timeD. How long answer D6. _______does your sister write to your parents?A. How manyB. How often c. How long D. How far answer B7. ________does it take you to finish you homework every day?A. How longB. How oftenC. How soonD. How much answer A反意疑问句考点反意疑问句是高考重要考点,其构成形式是"肯定+ 否定"和"否定+ 肯定",但也有一些特例。