It be 时间段 since,before....句型

It is +时间+since when before

It+be+时间+before/since/when/that句型辨析I since1. 翻译“It is/has been+时间段+since从句”(1)当从句谓语动词为非延续性动词时，表示这段时间从该动作开始时算起，即“自从做……以来已经多久了”。

(2)当从句谓语动词为延续性动词时，表示这段时间从动作结束时算起，即“自从不做……以来已经多久了”。

It is two years since he joined the army.他参军两年了。

(从参军那一刻算起)It is two years since he was a soldier.他退役两年了。

(从他不再是士兵算起)2. 时态主句为现在时（一般或完成），从句都是一般过去时。

主句为过去式（一般性都用was就够了），从句都是过去完成时II before1. 翻译It was/will be+时间段+before...过多长时间将发生某动作或事情；或过了多久发生了某事或动作。

It was three years before he finished the work.他花了三年才完成这项工作.It will be three years before he finishes the work.他得花三年才能完成这项工作. 2.It won't be/take long before...不久就会…It won't be long before he finishes the work.他不久就会完成这项工作.2. 时态主句为过去式（一般性都用was就够了），从句用过去时主句为将来时，从句用现在时（用一般现在时表示将来）III when1. 翻译It is + 时间点+ when…当发生什么的时候是什么时候…It was one o’clock when he came in .2. 时态主句是什么时态，从句就是什么时态3.常考与强调句的区别It was five o'clock when we arrived at the small mountain village.It was at five o'clock that we arrived at the small mountain village.强调句去掉it、be和that，余下的部分仍是一个完整的句子。

it+be+时间+before,since,when从句课件

It +be +时间+ before/since/when 从句
1. It is / has been + 一段时间 + since从句
如：It is 17 years since Hongkong returned to China.
香港回归已经有17年了。
在“It’s +时间段+ since从句” 句型中，如果since从句的谓语动词是瞬间性动词，表示肯定意义；如果since从句的谓语动词是延续
了多长时间之后才……” 例： It was long before they found their son. 过了很久他们才找到他们的儿子。
② 若主句是否定形式，翻译成 “没过多久就……” 例：
It was not long before the couple met again. 没过多久这对夫妻就见面了。
分析：since从句中的系表结构表示一种状态，这种状态是延续性的，表示否定意义，译为“不是，不当”
注：时间的计算一律从since从句的动作完成或状态结束时算起。
It is/has been two days since she fell ill. (她生病两天了） It is/has been two days since she was ill.
5. It was midnight _w__h_e_n___ he arrived home. 6. It was at midnight __t_h_a_t___ he
7a.rIrtivweadshnoomt eu.ntil midnight _t_h_a_t___ he arrived home.
强化习题：
ቤተ መጻሕፍቲ ባይዱ

It引导的时间状语从句总结与练习

高考It +be+ 时间+ 从句”结构总结一在“It +be+ 时间+ 从句”结构中，引导从句的从属连词有before, that, since, until （till ）, when 等。

这一结构是近几年高考常考的知识点，现将它们的用法小结如下：一、It +be （not ）+ 时间段+before 从句。

其中的主句是肯定式时，意为“过多长时间才……”；主句是否定式时，意为“没过多久就……”。

例如：1. It was not long before the whole country rose and drove the Austrian soldiers from their homeland. 不久，全国人民便奋起反抗，把奥地利军队从他们的国土上赶了出去。

2. It may be five or six years before the new medicine is tested on human beings.要过五六年时间这种新药才能在人身上做试验。

3. It was two months before he designed the bridge. 过了两个月，他设计出了这座桥梁。

二、It +will be （was ）+ 时间段+until 从句若主句中用一般将来时，则从句中用一般现在时，意思是从现在起到从句中谓语动词表示的动作发生时还有多长时间；若主句中用一般过去时，则从句中也用一般过去时，意思是从过去某一时间起到从句中谓语动词表示的动作发生还有多长时间。

例如：1. It will be ten days until my birthday comes. 到我生日还有十天。

2. It was only five minutes until her husband came back from work.当时离她丈夫下班只有五分钟了。

注意：结构“一”与结构“二”在肯定句中几乎可以通用。

时间状语从句before 和 since的用法

时间状语从句before 和since的用法before 和since的用法1.连词before表示“还未...就...；不到...就...；...才...；趁...还没...”Before they reached the station, the train had gone.他们(还没)到达火车站前，火车已经开走了。

We hadn’t run a mile before he felt tired.我们跑了还不到一英里他就累了。

Please write it down before you forget it.趁你现在没忘把它记下来。

2.before的句型：It will be +时间段+before从句，表示“多久之后才”。

It won't be long +before从句，表示“不久之后将...”It will be half a year before I come back.半年后我才回来。

(一般现在时表将来)It won’t be long before we meet again.不久后我们将再见面。

3.since的句型：It is/has been+时间段+since从句。

若从句的谓语为非延续性动词，表示“自从动作开始以来有多久了”；若从句的谓语为延续性动词，表示“自从动作结束/完成...有多久了”，常译为“自从不...有多久了”。

It is three years since the war broke out.战争爆发以来，有三年了。

It is twenty years since I've seen her. 我已经二十年没见她了。

五、every time, each time, next time, the first time, any time, all the time 的用法这些短语用来引导时间状语从句，表示“每当..；每次...；下次...”等。

高考It++be++时间+++从句”结构总结

高考It +be+ 时间+ 从句”结构总结一在“It +be+ 时间+ 从句”结构中，引导从句的从属连词有before, that, since, until （till ）, when 等。

这一结构是近几年高考常考的知识点，现将它们的用法小结如下：一、It +be （not ）+ 时间段+before 从句。

其中的主句是肯定式时，意为“过多长时间才……”；主句是否定式时，意为“没过多久就……”。

例如：1. It was not long before the whole country rose and drove the Austrian soldiers from their homeland. 不久，全国人民便奋起反抗，把奥地利军队从他们的国土上赶了出去。

2. It may be five or six years before the new medicine is tested on human beings.要过五六年时间这种新药才能在人身上做试验。

3. It was two months before he designed the bridge. 过了两个月，他设计出了这座桥梁。

二、It +will be （was ）+ 时间段+until 从句若主句中用一般将来时，则从句中用一般现在时，意思是从现在起到从句中谓语动词表示的动作发生时还有多长时间；若主句中用一般过去时，则从句中也用一般过去时，意思是从过去某一时间起到从句中谓语动词表示的动作发生还有多长时间。

例如：1. It will be ten days until my birthday comes. 到我生日还有十天。

2. It was only five minutes until her husband came back from work.当时离她丈夫下班只有五分钟了。

注意：结构“一”与结构“二”在肯定句中几乎可以通用。

Since用法before用法itis句型和therebe固定句型

发生已经有3天了。）
It was+一段时间+since从句
• It was+一段时间+since从句从句用had done）,主句用一般过去式.
• It had been+一段时间since 从句（did），主句had done
• It was three years since Jack had been a teacher.
延续性v.,翻译时直译) • eg. It is 5 years since I have lived here. (live为延续性v.故直译为：自从我住在这儿已经5年了。) 2. it is/has been +时间段n.+ since sb. did(如v.为短暂性v./
瞬间性v. 翻译时直译,如为延续性v./表示状态词翻译时反译) It is 5 years since I lived here. （live为延续性v.故反译为我已经5年不住这儿了。） It is 3 years since I smoked. （smoke为延续性v.故反译为我已经3年不吸烟了。）
• It had been three years since Jack was a teacher.
• 杰克不当老师已有3年了
• 1）在 “It was + 一段时间 + before从句句型中，若主句是一般过去式，从句也是一般过去式时：
① 若主句是肯定句，翻译成“过了多长时间
之后才……” 例：It was long before they found their son. 过了很久他们才找到他们的儿子。
It is+adj+doing
It is + useless (nice, good，interesting, expensive等形容词)+ doing sth． It is useless speaking.光说没用。

It be......句型归纳与辨析

It be…句型归纳与辨析同学们在平时学习过程中，经常遇到“It is / was…that / when / before / since…”，“It is / was the first / second / third…time that…”等类似的句型，往往因分不清这些句型的用法而做错题。

现将这些句型归纳如下，以便同学们对比掌握。

1. It is / was…that…包括两种句型：(1) It is / was…that（引导主语从句）It is clear that what he said is true.很明显他的话是对的。

(2) It is / was…that / who（强调句型）这个句型可以强调除谓语之外的任何句子成分，被强调部分是人时，还可以用who代替that引导从句。

It was in 1998 when he was in middle school that he was nearly drowned.他在1998年还在上中学时，他差一点被淹死。

2. It is / was+时间点+when从句这种从句有两种情况：(1) when为连词，引导时间状语从句，意为“当……的时候已是……时间了”。

It was four o”clock in the early morning when her husband came back.当她丈夫回来的时候已经是早晨4点了。

(2) when为关系副词，引导定语从句，意为“……是……时候”。

不过这个句型容易和强调句型混淆。

试区别：<1> It was 1998 when he went abroad.（定语从句）他是在1998年去国外的。

<2> It was in 1998 that he went abroad.（强调句型）他是在1998年去国外的。

句<1>中的“1998”是句中It was的表语，“when he went abroad”作“1998”的定语，而句<2>中“in 1998”是被强调句型所强调的状语部分，它的原句为：He went abroad in 1998 .3. It”s (high) time+(that)从句注意从句的谓语动词形式用“一般过去时或should+动词原形”，意为“是该干……的时候了”。

sincebefore的用法

It ' s 一段时间+ since从句在“ It '时间段+ si nee从句”句型中，如果si nee从句的谓语动词是瞬间性动词，表示肯定意义；如果since从句的谓语动词是延续性动词，则表示否定意义。

例如：1) It is / has been ten years since hl e ft Beijing.译文：自从他离开北京已经十年了。

分析：since从句中的left是leave的过去式，是瞬间性动词，表示肯定的意思, left 译为“离开”2) It is / has been ten years since hwe as a doctor.译文：他不当医生已经十年了。

分析：since从句中的系表结构表示一种状态，这种状态是延续性的，表示否定意义，译为“不是，不当”注：时间的计算一律从since从句的动作完成或状态结束时算起。

2. It was / will be + 一段时间+ before 从句1)在“It was +—段时间+ before从句” 句型中，若主句是一般过去式，从句也是一般过去式时：① 若主句是肯定句，翻译成过了多长时间之后才……”例：It was long before they found their son.过了很久他们才找到他们的儿子。

② 若主句是否定形式，翻译成“没过多久就……”例：It was not long before the couple met again.没过多久这对夫妻就见面了。

2）在“It will be + 一段时间+ before从句”句型中，若主句是一般将来时，从句也是一般现在时：① 若主句是肯定句，翻译成“要过多长时间之后才例：It will be half a year before I come back. 半年后，我才回来。

② 若主句是否定形式，翻译成用不了多久就…例：It won 't be long before we meet again. 我们不久就会见面。

It …+点时间段时间+before…诠释

It …+点时间/段时间+before…诠释高中英语中，before句式，相似性强，考生易混淆，究其用法，现小结于后，敬供商榷。

1. It was / will be + 段时间+ before …在“It was / will be + 段时间 + before 从句”结构中，before是从属连词，表示“……才；……就”，引导时间状语从句。

例：It was just 3 days before the book was published.三天后那本书就出版了。

例：It will be five years before we meet again.五年后我们才会在见面。

2. It wasn’t long before …/ It won’t long before …在“It wasn’t long before从句”结构中，before是从属连词，表示“不久以后就……”；而“It won’t long before从句”结构中，before是从属连词，意为“不久就会……”，引导时间状语从句。

例：It wasn’t long before he came home.他不久后才（很快）回到了家里。

例：It won’t long before you get well again.不久你就可以恢复健康了。

3. It be + 点时间+ before …在“It be +点时间 + before从句”结构中，before是从属连词，表示“在……之前；时间是……”，引导时间状语从句。

例：It was 4:00 before he came to see you.他是四点后来看你的。

4. It be + 点时间+ when …在“It be +点时间 + when从句”结构中，when是从属连词，表示“当时是……”，引导时间状语从句。

例：It was 4:00 when he came to see you.他来看你时，已是四点了。

It +be +时间段+since句型及其拓展

小贴士
(1)since引导的从句中的动词常用非延续性动词，翻译时是肯定的，表示“自从……”。 Mr.Li has been here since he came back. 自从李先生回来以后，他一直在这儿。 (2)since引导的从句中的动词为延续性动词，翻译是否定的，表示“自从不……” It is/has been 5 months since he lived in Beijing. 他已经有5个月不住在北京了。
B．before C．after D．since
3．It is several months________the whole country started
to talk about whether driving after drinking alcohol
ห้องสมุดไป่ตู้should be punished.
①Well, _i_t _is_/_h_a_s_b_e_e_n_ many years _s_in_c_e_ we first met.How time flies！嗯，我们好多年没见了。时间过得真快！ ②_I_t_w_a_s_ some time __b_e_fo_r_e_ the government looked into the case.一段时间后政府才调查这个案子。 ③_I_t_w_a_s_ 12 a．m. _w_h_e_n_ I got up. 当我起床时，已经是中午12点了。 ④_I_t_w__a_s yesterday _t_h_a_t_ the news was broadcast on TV. 是在昨天电视上播放了这条新闻。
对点训练一：
①It has been 20 years sincheegraduated from the school.

＂It be+时间+when／before／since／that＂句型辨析

这么开心了。” 所以选择Ｄ项。
四、 “ Ｉｔｉｓ（ｗａｓ）＋被强调部分＋ｔｈａｔ（ｗｈｏ）＋句子的剩余部分 ” 是强调句型的基本结构。对
强调句的考查主要体现在用它来强调句中的主语、宾语、状语或状语从句。把需要加强语气的部分放在 “ Ｉｔｉｓ（ｗａｓ） ” 之后。如果被强调部分主语是人时，可用连词ｔｈａｔ或ｗｈｏ；如果被强调部分是物时，只能用连词ｔｈａｔｏ一般来讲，原句的谓语动词如果是现在或将来的某种
—
—
Ｉｅｎｊｏｙｅｄｍｙ．
ｓｅｌｆＳＯｍｕｃｈ．
Ａ．ｗｈｅｎ
Ｂ．ｔｈａｔ
Ｃ．ｂｅｆｏｒｅ
Ｄ．ｓｉ ห้องสมุดไป่ตู้ ｃｅ
解析
如果去掉Ｉｔｉｓ（ｗａｓ） …，还是一个完整的句子，则是强调句。而本句去掉Ｉｔｉｓ和
（１）（２０１２年湖南卷）ＩｔｗａｓｎｏｔｕｎｔｉｌＩｃａｍｅｈｅｒｅ— —
ｍｏｕｓｆｏｒｎｏｔｏｎｌｙｉｔｓｂｅａｕｔｙｂｕｔａｌｓｏｉｔｓｗｅａｔｈｅｒ．
（１）（２０１１年四川卷）Ａｓｉｔｒｅｐｏｒｔｅｄ，ｉｔｉｓ１００ｙｅａｒｓ

It since it before 句型和练习

It+be+时间+before/since/when/that句型辨析I. since1.It is/has been+时间段+since sb did sth某个动作发生持续多久eg:It is/has been three years since he finished the work.自从他完成这项工作已经三年了.2.该句型中若since后跟延续性动词，要翻译成否定含义,即“没做某事已经多久了”.eg:It has been three years since he worked here.他不在这工作已经三年了.It has been three years since he smoked.他已经戒烟三年了.但是：It has been three years since he began to smoke.他吸烟有三年了。

II.before.1.It was/will be+时间段+before... 过多长时间将发生某动作或事情；或过了多久发生了某事或动作。

eg:It was three years before he finished the work.他花了三年才完成这项工作.It will be three years before he finishes the work.他得花三年才能完成这项工作.2.It won't be/take long before...不久就会…eg:It won't be long before he finishes the work.他不久就会完成这项工作.III when.when没有固定与It is…连用的句型.when可表示时间点或时间段，因此从句中短暂性动词或延续性动词均可用.when还可作并列连词，表示突然发生一个动作,等于and at that time.常用句型:1主语+was/were doing when...2主语+was/were about to do when...It+be+时间+before/since/when/that重要考点练习It +be+时间+before/since/when/that…是高考中每年必考的重要考点，而学生却对这个句型中几个关联词的选择把握不准，造成失分。

It+be+时间+从句

It+be+时间+从句归纳1. I t is/has been+时间段+since+一般过去时自从...以来已有...久了例1：It is/has been 10 years since he came here.这类句型可转化为：=Ten years has passed since he came here.这一句型可扩展为：It was+时间段+since(从句用过去完成时)例2：It was years since he had arrived in China.(过去时+since+过去完成时)He said it was two years since he had joined the army.他说他当兵已有两年了。

需要注意的是since从句的谓语动词一般是非延续性动词，但有时也可用延续性动词或表示状态的词，此时需要注意句子的翻译（瞬顺延反）：例3：It is three years since she came to our class.她来我们班已经有三年了。

It is three years since she was in our class.她离开我们班已经有三年了。

It is half a year since he was ill. 他病愈有半年了。

It is half a year since he smoked.他戒烟有半年了。

2. It+was+时间点+when (从句用一般过去时) 某事发生在什么时间It will be+时间点+when (从句用一般现在时表将来)it指时间，点时间前没有介词，when引导的从句是时间状语从句。

例1：It was already 8 o’clock when he came back.当他回家时已经8点了。

例2：It will be midday when they get home.当他们到家时将是中午。

3. I t+will(not) be +时间段+before+现在时It was(not)+时间段+before+过去时肯定形式表示"过......时间才......”，否定形式表示"没有过......就......"例1：It will be another year before he comes here.例2：It was not long before he came home.不久他就回来了It was some time ___ we realized the truth.A.whenB.untilC.sinceD.before正确答案：D。

it + be +时间 +从句用法总结

在语法填空和短文改错中it+be+时间+从句是一个常考的句式，可是学生常常会因为判断失误而选错从句的关联词。

其实只要细心这一句式还是有规律可循的。

1. It was / will be +时间段+before...表示“过多长时间才......".在否定句中，表示”没过多长时间就......“。

如：It will be two years before we get married. 我们要过两年才结婚。

It was not long before he left. 不久之后他就走了。

2. It is / has been +时间段+since... 表示”自从......以来有......时间了",此时从句时态常用一般过去时。

It is just a month since I moved here. 我搬到这儿刚好一个月。

It has been ten years since we lived here. 我们没住这儿已经十年了。

3. It was / will be + 时间点+ when...It was seven o'clock when I got to school this morning. 我是早上七点到学校的。

4. It is / was +时间状语+that... 这是强调句型的考查It was at six o'clock this morning that they set out. 他们是在今天早上六点动身的。

5. It is / was + not until... + that ... 这个句式考查的也是强调句型It was not until he took off his sunglasses that I recognised that he was a famous film star. 直到他摘下眼镜我才认出他是一个著名的影星。

Itbe+时间段+since句型高三二轮复习语法专题

It was long before they escaped from the prison.
3、“It be ＋时间点＋when从句. 表示“在某时, 做某事”。
（1）、时态的运用：从句中时态与be一致. It+ was+时间点+when-clause
① (be用一般过去时，从句谓语用一般过去时) It+ will be+时间点+when-clause ② (be用一般将来时，从句谓语用一般现在时表将来)
“It be＋时间段＋ since ...”句型
一、注意四个句型：
1、 It be＋时间段＋since从句 2、 It be ＋时间段＋before从句 3、 It be ＋时间点＋when从句 4、It be＋介词＋时间点/段＋
that从句”为强调句型。
二、句型讲解：
1、 It be＋时间段＋since从句。意为“自从…… 以来已有多长时间了”。
It was at 11 o'clock that he came back last night. = He came back last night at 11 o'clock.
(注意：看有没有介词）
It was 11 o'clock when he came back last night.
(2)、判断方法：去掉it、be和that，余下的部分仍是一个完整的句子，这样的句子一定是强调句。 ①看时间前有没有介词（有介词是强调句）。
2、-Did Jack come back early last night？ -Yes. It was not yet eight o‘clock___B____ he arrived home A. before B. when C. that D. until

It引起地几个易混淆地时间句型

It引起的几个易混淆的时间句型在学习中，同学生们对“It + be + 时间 + 从句”这个结构经常混淆不清，下面逐一进行分析。

1. It + be + 时间 + since-clause这个句型表示从since 从句谓语动作发生以后到现在或过去所经过的一段时间，意为“自从......以来已多久了”，主句多用一般现在时，从句用一般过去时，如果表示过去的情况，主句用一般过去时，从句用过去完成时，或主句用过去完成时，从句用一般过去时。

例如：It is three years since his father passed away . (从现在算起)It was 10 years since they married . (从过去算起)It had been fifteen years since she left Shanghai . (从过去算起)30 years has passed since we joined the Party . (从现在算起)2. It + be + 时间 + before-clause这个句型中的时间一般为表示一段时间的词语(如：long years , months , weeks , days ,hours , minutes ) ，主句中的谓语动词用肯定式，意为“过多长时间才......”。

主句的谓语动词是否定式时，意为“没过多长时间就......”。

主句的时态可用过去时was 或将来时will be；用was 时，before从句的动词用一般过去时；用will be 时，before 从句常用一般现在时。

例如：It was not long before she learned those poems by heart . 她没过多久就背会了那些诗歌。

It was long before the police arrived .过了很久警察才来。

It will be hours before he makes a decision . 要过好几个小时他才会作出决定。

It…点时间段时间before…诠释

It …+点时间/段时间+before…诠释高中英语中,before句式,相似性强,考生易混淆,究其用法,现小结于后,敬供商榷;1. It was / will be + 段时间+ before …在“It was / will be + 段时间 + before 从句”结构中,before是从属连词,表示“……才；……就”,引导时间状语从句;例：It was just 3 days before the book was published.三天后那本书就出版了;例：It will be five years before we meet again.五年后我们才会在见面;2. It wasn’t long before …/ It won’t long before …在“It wasn’t long before从句”结构中,before是从属连词,表示“不久以后就……”；而“It won’t long before从句”结构中,before是从属连词,意为“不久就会……”,引导时间状语从句;例：It wasn’t long before he came home.他不久后才很快回到了家里;例：It won’t long before you get well again.不久你就可以恢复健康了;3. It be + 点时间+ before …在“It be +点时间 + before从句”结构中,before是从属连词,表示“在……之前；时间是……”,引导时间状语从句;例：It was 4:00 before he came to see you.他是四点后来看你的;4. It be + 点时间+ when …在“It be +点时间 + when从句”结构中,when是从属连词,表示“当时是……”,引导时间状语从句;例：It was 4:00 when he came to see you.他来看你时,已是四点了;5. It be + 段时间+ since …在“It be +段时间 + since从句”结构中,since是从属连词,引导时间状语从句;若从句中谓语动词是短暂性动词,表示“自从……以来有多久了”；若从句中谓语动词是延续性动词,则表示“多久不……了”;例：It was two years since I joined the League member.我入团已三年了;join是短暂性动词例：It was many years since I enjoyed myself like this.我已有多年没有像这么开心了;enjoy是延续性动词6. It be + 时间+ that …在“It be +时间 + that从句”结构中,构成强调句,表示“就是……时间才……”;例：It was two years later that I came back from abroad.正是两年后我才回国的;7. It is / will be + 段时间+ until …在“It is / will be +段时间 + until从句”结构中,until是从属连词,引导时间状语从句,表示“过了要过多久才……”,until相当于before;例：It would be 10 years until / before he knew the truth.十年后他才得知真相;温馨提示1until用于肯定句,表示“直到……为止”,谓语动词一般是延续动词,常见的有stay, work, study, play等,表示动作一直延续到until所表示的时间为止;例：Tell him to stay up until I get back..告诉他,等我回来后再去睡;2until用于否定句,表示“在……之前；直到……才”,谓语动词一般是终止性动词,常见的有come, arrive, leave, die等,表示动作到until所表示的时间时才发生;例：They won’t come to any decision until they had a chance to discuss it wholly.等有机会全面讨论这个问题后才定夺;综合上述,句子结构千变万化,规则众多,用法奇特,但只要根据已有的学习经验和知识水平分析句子,理解用意,进一步进行信息整合,推理判断,便可找到更新的理解办法或途径,这样,无论多么难的句子都可以一一化解了;经典演练1. It was _____ he came back from Africa that year ____he met the girl he would like to marry.A. when; thenB. not; untilC. not until; thatD. only; when2. --- Have you know Dr. Jackon for a long time--- Yes, since she ____ the Chinese Society.A. has joinedB. joinsC. had joinedD. joined3. --- Did his father come back early last night--- Yes, it was not yet eight o’clock ___ he arrived home.A. beforeB. whenC. thatD. until答案与解析1. C 考查强调句与时间状语从句辨析;句意：正是他那一年从非洲回来时,他才遇到了他的确想要结婚的那位姑娘;此处应是强调句型,被强调的对象是“not until he came back from Africa that year ”,不是时间状语从句,而选项A,B和D项不合要求,故C项正确;2. D 考查since时间状语从句;句意：自她加入汉语协会以来;据语境分析,此处since表示“自从……以来”,而选项A,B和C均不合语义,故D项正确;3 B 考查when时间状语从句;句意：当他回到家里时,还不到八点;据语境分析,此处it指时间,when引导时间状语从句,表示“当……时候”,而选项A,C和D均不合语义,故B项正确;能力提升1. --- How long do you think it will be ____ China sends a manned spaceship to the moon--- Perhaps two or three years.A. whenB. untilC. thatD. before2. It was some time later ___ we realized two or three years.A. untilB. beforeC. thatD. since3. How long is it ___ we last saw each other in ShanghaiA. sinceB. beforeC. untilD. that4. That was really a special evening, it’s years ___ he enjoyed himself so much.A. whenB. thatC. beforeD. since5. It seemed only seconds ___ the boy finished washing his face.A. whenB. beforeC. afterD. since6. --- What did she want to know, Tom--- She wondered ____ we could complete the experiment.A. when was itB. it was when thatC. it was whenD. when it was that7. Was it in 1939 ___ the Second World War broke outA. thatB. whenC. untilD. since8. It was two years ___ I began to learn English.A. whenB. sinceC. beforeD. that9. It was not until dark ___ he found ___ he thought was the correct way to solve the problem.A. that; whatB. that; thatC. when; whatD. when; what答案与解析考查before时间状语从句;句意：--- 你认为中国多少时间后才能把宇宙飞船发射到月球上呢--- 或许两三年吧;据语境分析,此处before引导时间状语从句,表示“在……之前,……才”,而选项A,B和C均不合语义,故D项正确;考查强调句与时间状语从句辨析;句意：就是一段时间以后我们才能弄清事实的真相;据语境分析,此处强调“some time later”, It be …that …构成强调句式,而不是时间状语从句,而选项A,B和D均不合句式要求,故C项正确;考查since时间状语从句;句意：我们最后一次自在上海见面后有多长时间了呢据语境分析,此处应是since引导时间状语从句,表示“自……以来”,而选项B,C和D均不合语义,故A项正确;4. D 考查since时间状语从句;句意：那是一个特别的晚上,已有多年没有这么开心了;据语境分析,此处应是since引导时间状语从句,表示“自……以来”,而选项A,B和C均不合语义,故D 项正确;5. B 考查before时间状语从句;句意：好像没大一会儿,那个小孩就把脸洗完了;据语境分析,此处应是before引导时间状语从句,表示“….才”,而选项A,C和D均不合语义,故B项正确;6. D 考查强调句与时间状语从句辨析;句意：--- 她到底想知道什么,Tom--- 她想知道我们完成这项实验的时间;据语境分析,此处应是强调句,被强调的对象是“when”,又因放在she wondered之后,随之构成宾语从句,将when提出以平衡句子,表示“….时候”,而选项A,B和C均不合要求,故D项正确;7. A 考查强调句与时间状语从句辨析;句意：就是在1939年爆发的第二次世界大战吗据语境分析,此处应是强调句型,被强调的对象是“in 1939”,不是时间状语从句,而选项B,C和D均不合要求,故A项正确;8. B考查since时间状语从句;句意：我自学英语以来,有两年时间了;据语境分析,此处应是since引导时间状语从句,表示“自……以来”,而选项A,C和D均不合语义,故B项正确;9. A 考查强调句与时间状语从句辨析;句意：直到天黑时,他才发现他所想到的正是解决这个问题的有效途径; 据语境分析,此处应是强调句型,被强调的对象是“not until dark”,又在he found后跟了一个what引导的宾语从句,不是时间状语从句,而选项B,C和D均不合要求,故A 项正确;be +时间段＋before...过了多长时间才.：It was two days before he knew.过了两天他才知道.It was three years before he came back from abroad.过了三年他才从国外回来.be+ 时间点＋when...当.时候,时间是.：It was six when he arrived.当他到达时,时间是6点钟.is / has been +时间段＋since...往往用非延续性动词自从……以来到现在已有多久,做.已经多长时间了：It is / has been five years since he died.他已经死了5年了.is three years since they got married.他们已经结婚三年了.It is three years since they were married.他们已经离婚三年了.若since引导的状语从句的谓语动词是持续性动词或表示状态动词的过去时时,则从句表示的时间是“从动作或状态结束时算起”.再如:It has been quite some time since I was last in London.我上次离开伦敦至今颇有一段时间了. won't be long before...:不久.It won't be long before we meet again.我们不久会再见面.。