考试知识点27 时间状语从句
高考考试频度：★★★★★
考向一 when/while/as引导的定语从句
1、when引导的时间状语从句
1. when引导的时间状语从句，其动词既能够是延续性动作的动词，也可以是瞬间性动作的动词，而且可以表示主句的动作和从句的动作同时发生，或者从句的动作发生在主句的动作之前。
When you apply for a job, you must present your credentials. 当你申请工作时，你需要递交你的有关证件。（同时）
When the students heard the teacher’s footsteps, they all aTOPped talking. 当学生们听到老师的脚步声时，他们都停止了讲话。（从句动作发生在前）
2. when还可表示just then（正在那时，忽然）的意思，此时其所引导的从句只放在主句之后。
be about to do ... when ... 正要去做某事，忽然……
be doing ... when ... 正在做某事，忽然……
be on the point of doing ... when ... 正在做某事，忽然……
We were about to start when it began to rain. 大家正要动身，忽然天下起雨来。
The game had hardly/scarcely/barely begun when it started raining. 比赛刚最初就下起雨来。
2、while引导的时间状语从句
while表示＂在某一段时间里＂或＂在……期间＂，其所引导的从句的动作是延续性的，并侧重表示和主句的动作同时发生。
When the teacher paraphrased the text in English, the students listened attentively and took notes. 当老师用英语讲解课文时，学生们聚精会神地听并做着笔记。
I can learn while I work. 我可以边工作边学习。
3、as引导的时间状语从句
as引导的时间状语从句其动词的动作是延续性的，而且侧重表示主句和从句的动作交替或同时发生，译为＂一边……，一边……＂或＂伴随……＂。
We were having breakfast as she was combing her hair. 她梳头时大家在吃早饭。
It will warm up a little bit on Sunday as the cold front passes. 寒流一过，星期日就会有点暖意了。
1.（2016·全国新课标卷III·语法填空）Over time, __________ the population grew, people began cutting food into small pieces so it would cook more quickly.
【参考答案】as/when
【答案分析】考查时间状语从句。句意：伴随人口的增长，大家开始把食物切成小块，如此可以煮得快一点，这里是时间状语从句，when意为＂当……的时候＂，后跟长动作或短动作，故填as／when。
2.（2016·四川卷·语法填空）The mother held the baby in her front paws much the way a human does. __________________________________________________ it cried, she rocked it back and forth and gave it little comforting pats.
【参考答案】When/If
【答案分析】考查时间状语从句。句意：假如或当它哭的时候，她会前后摇动。故填When/If。
考向二before引导的时间状语从句
1、before的容易见到意思
1. before＂在……之前＂。
I have finished my dissertation before my supervisor went abroad. 在我的导师出国之前，我已完成了我的学位论文。
I’ll be back before you have left. 你离开之前我就会回来。
2. before＂……之后才＂。
It may be many years before we meet again. 可能要过很多年大家才能再见了。
It was three days before he came back. 他三天后才回来。
3. before ＂尚将来得及 ＂
Before she could move, she heard a loud noise, which grew to a terrible roar. 她还没来得及动弹，就听见有非常响的声音，接着就成了可怕的隆隆轰鸣声。
Before they reached the house, a new great wave came, sweeping down trees, and sweeping them down too. 他们还没有到屋子，又一个巨浪打来，冲倒了树，也冲倒了他们。
4. before ＂要……先……＂
You should be a pupil before you become a teacher. 要当老师，先作学生。
5. before＂趁……＂
You should do it before it is too late. 趁目前还不算太晚，你应该赶快做它。
2、学会热门句型使用方法
1. it was（not）/had done＋一段时间＋before（vt-ed）…＂还要过多长时间才……（不多长时间就……了）＂
It was not long before he returned to Beijing. 不久他就回到北京。
It was long before he married Wei Fang. 过了很长时间他才娶魏芳。
2.it will（not）be＋一段时间＋before（一般式）… ＂还要过多长时间才……（不多长时间就……了）＂
It will be long before he goes abroad. 要过很长时间他才出国。
3.there is +一段时间+to go（=left）＋before（一般式）... ＂在……之前＂
4.long before ＂不久前＂, 用于一般过去时和完成时中；before long = soon/not long after ＂不久后＂，用于一般以后时和一般过去时中。
1.We need to get to the root of the problem ______________ we can solve it.
A. while B. after C. before D. as
【参考答案】C
【答案分析】考查时间状语从句的连接词。句意：在大家解决问题之前，大家需要找到问题的根源。A. while当……的时候，而；B. after在……之后；C. before 在……之前；D. as正如。依据句意可知选C。
2.It ________ long before we ________ the result of the experiment.
A. will not be；will know B. is；will know
C. will not be；know D. is；know
【参考答案】C
【答案分析】句意：不会过非常长一段时间大家就会了解实验结果。应用It was not long before的革新句型It will not be long before，before引导时间状语从句时，从句应用一般目前年代替一般以后时。
2.Scientists say it may be five or six years ________ it is possible to test this medicine on human patients.
A. since B. after C. before D. when
【参考答案】C
【答案分析】该句型也是It was not long before的革新句型。句意：科学家说或许再有5年时间这种药就能在人类身上做实验了。
考向三as soon as/once/directly/the instant等引导的时间状语从句
as soon as 是最容易见到的表示＂一……就……＂的从属连词，其他连词还有once（一旦），directly（老式英国英语），immediately（主要用于英国英语），instantly，the instant ，the minute ，the moment等，它们一般都可与as soon as换用。
As soon as we got home, the telephone rang. 大家一到家，电话就响了。
I recognized her immediately I saw her. 我一看见她就认出她来了。
Directly the teacher came in everyone was quiet. 老师一进去，大伙就静了下来。
考向四 hardly...when/no sooner...than引导的时间状语从句
hardly/barely/scarcely...when和no sooner...than的意思是＂刚……就＂，它们所引导的从句中的谓语动词一般为过去完成时。
He had no sooner arrived home than he was asked to start on another journey. 他刚一到家，就又要他出另一次差。
★ hardly/barely/scarcely和no sooner置于句首时，从句要倒装。
No sooner had the words been spoken than he realized that he should have remained silent. 这类话刚一出口，他就意识到自己应该维持沉默。
考向五since引导的时间状语从句
在含有since引导的时间状语从句的复合句中，从句的谓语动词一般为一般过去时，主句的谓语动词一般为目前完成时。
We’ve never met since we graduated from the college. 大学毕业后大家就再没见过面。
Great changes have taken place since you left. 你走了将来，这里发生了巨大的变化。
1.（2017·天津卷·完形填空）She had been talking to her mother about the lives of homeless people__________they first saw the homeless man.
A. since B. unless C. although D. as
【参考答案】A
【答案分析】考查连词。A. since 自从B. unless 除非C. although尽管D. as由于。句意：自从他们首次看到无家可归的人，Hannah就一直在跟她的母亲说流浪者的生活，依据句意可知选A。
2.I have heard a lot of good things about you __________I came back from abroad.
A. since B. until C. before D. When
【参考答案】A
【答案分析】考查状语从句。题干中主句谓语动词用目前完成时，从句中谓语动词用一般过去时，由题干意思可知所填词意思是：自从，因此用since引导时间状语从句。句意：自从我从海外回来后，我已经听说了不少关于你的好事。
考向六till/until引导的时间状语从句
till和until同义，作＂直到……时＂解，till多用于非正式文体，until多用于句首。
Donald will remain in college until he finishes his Ph.D course. 唐纳德将留在学校直到完成他的博士学位课程。
I won’t go with you until I finished my homework. 等我完成作业我才和你一块去。
注意：
not until 置于句首，主句要倒装。
Not until 4:00 in the morning can he fall asleep.
直到凌晨4点他才睡着。
Not until he returned did we have supper.
直到他回来大家才吃晚饭。
If you don’t understand something, you may research, study, and talk to other people _______ you figure it out.
A. because B. though C. until D. since
【参考答案】C
【答案分析】A. because 由于 B. though尽管 C. until 直到 D. since自从。句意：假如你没办法理解某个东西，你或许会去研究，学习并和别人探讨直到你解决为止，依据句意可知使用until“直到”，选C。
考向七each time/every time等引导的时间状语从句
这种连词主要有every time，each time， next time，any time， last time，the first time, by the time。如：
You can call me any time you want to. 你随时都可以给我打电话。
Each time I went there, I saw him working. 我每次去那儿都看见他在工作。
Every time I see her I'll think of it. 每次我看到她，我就想起这事。
Next time you come in, please close the door. 下次你进去，请关门。
He didn't tell me the last time I saw him. 我上次见到他时他没告诉我。
The first time I heard about the firm closing down was when George told me.
我刚开始听到公司破产的消息是乔治告诉我的。
By the time, he was taken to the hospital he was nearly dead.
他被送到医院时已经几乎不可以了。
注意：every time, each time, any time前不需要冠词， next time, last time中的冠词可以省略，而the first time中的冠词一般不可以省略。
题组一 能力过关
I．单项填空
1. It was 3 in the morning ___________ the earthquake happened. Hundreds were killed, with a lot ___________ in the collapse.
A. that；buried B. when；buried
C. that；burying D. when；burying
2. __________ it comes to traffic rules, I often come across such cases __________ the local drivers obviously know them but won’t follow them.
A. If；why B. When；which
C. Once；as D. When；where
3. Every time __________ they met, they would talk excitedly for several hours about the schoolmates and incidents __________ they still remembered in the primary school.
A. that；who and which B. when；that
C. /；that D. when；which
4. Many people have heard of the ＂brain drain＂. This is ___________ happens __________ people with good skills and a good education move to other country for study or work, often at great expense to their home countries.
A. which；when B. what；that
C. what；when D. why；when
5. —Glad to see you, Kate.
—Oh, my God. It’s been 20 years ___________ we last saw each other.
A. when B. before
C. after D. since
6. He smiled politely ____________ Mary apologized for her drunken friends.
A. as B. if
C. unless D. though
7. ___________ the poem a second time, the meaning will become clearer to you.
A. Having read B. While reading
C. If reading D. When you read
8. The police set about arresting the suspect ___________ they found enough evidence to prove him guilty.
A. immediate B. as long as
C. the moment D. as far as
9. The police had to employ force ___________ the crowd got out of control.
A. the instant B. at the instant
C. in an instant D. for an instant
10. If individuals are awakened ___________ they begin a dream phase of a sleep, they are likely to become irritable even though their total amount of sleep has been sufficient.
A.as if B. now that
C. each time D. first time when
II.语法填空
Eating organic food will not make you healthier, according to researchers at Stanford University, although it could cut your __________ to pesticides.They looked at more than 200 studies of the content and __________ health gains of organic and non-organic food. Overall, there __________ no difference in the nutritional content, although organic food was 30% less likely __________ pesticides.
The researchers looked at 17 studies comparing people who ate organic food __________those who did not and 223 studies __________compared the levels of nutrients, bacteria and pesticides in various food. However, none of the human studies ran for longer than two years, __________ conclusions about long-term __________ impossible. And all of the available evidence was __________ weak and variable, which the researchers said was unsurprising because of all the different variables.
Dr Crystal Smith-Spangler, the lead researcher, said "Some believe organic food is always healthier and more nutritious. But as __________matter of fact there isn’t much difference between organic and conventional food, if you’re an adult and make decisions based simply on your health."
题组二体验考试真题
1.（2018·北京卷·完形填空）To think he is sleeping on the streets tonight __________ he could have stolen the money and paid for a place to stay in.
A. when B. if C. where D. because
2.______ the average age of the population increases, there are more and more old people to care for.
A. Unless B. Until
C. As D. While
3.（2016·浙江）______online shopping has changed our life , not all of its effects have been positive.
A. Since B. After
C. While D. Unless
4. We need to get to the root of the problem______ we can solve it.
A. while B. after
C. before D. as
题组一 能力过关
I．单项填空
1. B
【分析】考查连词和非谓语动词。依据句子结构可知the earthquake happened是时间状语从句，应用when引导；第二空动词bury应用非谓语动词作a lot的宾语补足语，且与a lot之间是逻辑上的被动关系，故用buried，选B项。
2. D
【分析】考查时间状语从句和定语从句。句意：当说到交通规则的时候，我常常遇见这种情况，当地司机非常显然了解这类规则，但不想遵守它们。第一空用when引导时间状语从句，when it comes to sth当说到……的时候，第二空引导定语从句，case作先行词表示状况时，用关系副词where。故选D。
3. C
【分析】考查状语从句和定语从句。句意：每次见面，他们都会开心地聊上好几个小时关于小学时的同学和事情。every time可直接引导时间状语从句，无需再加连接词，第二个空为定语从句，当先行词既有人又有物时，关系代词用that，故C项正确。
4. C
【分析】考查表语从句和时间状语从句。句意：很多人都听说过＂人才外流＂。这是当有好技能和好的教育的人搬到另外一个国家学习或工作的时候发生的事情，常常以他们的祖国作为代价。第一空是引导表语从句，从句缺主语，用what引导，第二空是引导时间状语从句，用when引导。故选C。
5. D
【分析】考查连词。句意：——凯特，非常高兴见到你。——天啊！自从大家上次相见已经20年了。A. when＂当……的时候＂；B. before＂在……之前＂；C. after＂在……之后＂；D. since＂自从＂。since引导时间状语从句，从句的时态用一般过去时，而主句中用目前完成时。故选D。
6. A
【分析】句意：当玛丽为她醉酒的朋友道歉的时候，他有礼貌地笑了笑。此处as引导时间状语从句，表示＂当……的时候＂。if＂假如＂，引导条件状语从句；unless＂除非＂，引导条件状语从句；though＂尽管＂，引导让步状语从句。
7. D
【分析】考查时间状语从句。句意：当你第三阅读这首诗的时候，它的意思将变得更明确。逗号后面的句子主语是the meaning，前面动词是read，the meaning不是read的逻辑主语，不可以用非谓语动词作状语，要用when引导时间状语从句。故选D。
8. C
【分析】the moment意为＂一……就……＂，引导状语从句。句意：警察一学会足够的证明他有罪的证据后就开始着手逮捕这个嫌疑有。
9. A
【分析】考查连词短语。句意：人群一旦失去控制，警察不能不动用武力。the instant是连词短语，意为＂一……就＂；at the instant在那个瞬间；in an instant非常快；for an instant一会儿。故选A。
10. C
【分析】考查时间状语从句。句意：假如大家在一个开始做梦的睡眠阶段被吵醒，他们可能变得急躁，即便他们的睡眠总量是足够的。as if 表示＂宛若＂；now that表示＂既然＂；each time表示＂每次＂，多用来引导时间状语从句；first time when表示＂首次当……的时候＂，故选C。
II.语法填空
【文章大意】本文是一篇说明文。研究表明，吃有机食物并不会叫你更健康。
1.exposure
【分析】考查名词。据斯坦福大学的研究者所说，吃有机食物不会叫你更健康，尽管它能叫你少接触杀虫剂。依据空前的"your"及空后的介词"to"可知，此处应填名词。exposure"遭受，接触"。
2.associated
【分析】考查形容词。此处指他们研究了有机食物和非有机食物的所含之物和有关的健康效益。空处作定语修饰名词短语"health gains"，故应填形容词。associated"有关联的，有关的"。
3.was
【分析】考查时态和主谓一致。依据句中的"was"及此处陈述的是过去研究的结果可知，此处应用一般过去时;又因主语为"no difference"，故谓语动词应用第三人称单数。故填was。
4.to contain
【分析】考查非谓语动词。be likely to do sth.是固定结构，意为"大概做某事"，故此处应填不定式to contain。
5.with
【分析】考查介词。此处指研究者将吃有机食物的人和不吃有机食物的人作比较。compare...with... 是固定搭配，意为"比较……，与……相比"。
6.that/which
【分析】考查定语从句。剖析句子结构可知，空处在此引导定语从句，且在从句中作主语，先行词是"223 studies"，故填关系代词that/which。
7.making
【分析】考查非谓语动词。剖析句子结构可知，句子中已有谓语动词"ran"，故此处应填非谓语动词。又因动词"make"与其逻辑主语"none of the human studies"之间是主谓关系，故此处应用目前分词作结果状语。
8.outcomes
【分析】考查名词复数。outcome"结果，后果"为可数名词且其前无限定词修饰，故此处应用其复数形式outcomes。
9.relatively
【分析】考查副词。此处应用副词修饰形容词"weak and variable"，故填relatively"相对地"。
10.a
【分析】考查冠词。as a matter of fact"事实上"是固定搭配。故填不定冠词a。
题组二 体验考试真题
1.A
【分析】考查状语从句引导词。A. when在……状况下，既然；B. if假如；C. where表地址；D. because由于。在Tom本来可以偷了钱去支付一个可以睡觉的地方的状况下，他仍然选择了露宿街头（没偷钱）。所以Mr. Anderson对Tom的行为感到非常惊讶。A选项正确。
2.C
【分析】句意：伴随人口平均年龄的增长，愈加多的老人要照顾。unless除非；until直到；as由于，正如，伴随；while虽然，然而，当……时候。依据语境，故选C。
3.C
【分析】句意：尽管网购已经改变了大家的生活，单数不是所有些影响都是积极的。while引导让步状语从句，意为＂尽管，虽然＂；since既然，自从；after在……之后；unless除非。故选C。
4.C
【分析】句意：在大家解决问题之前，大家需要找到问题的根源。while当……时候，而； after在……之后； before 在……之前； as正如。依据句意可知选C。
