* * * * * * * * * * * * * * * * * * * * * 三、几种让步状语从句的用法区别 1．though, although, as引导的让步状语从句的区别 although引导正常语序的让步状语从句；though既可以引导正常语序的让步状语从句，也可以引导倒装语序的让步状语从句；as引导倒装语序的让步状语从句。 Although/ though he has limited technical knowledge, the old worker has a lot of experience. as引导让步状语从句时，要把作表语的形容词、名词，作状语的副词或谓语的一部分提到句首，如果是单数名词作表语，把它提到句首时，其前不用冠词。分为以下几类： (1)“名词＋as＋主语＋其他”构成让步状语从句，单数名词前不加冠词。 Scientist as he is, he is still as modest as before, which always moves all the people who know him.(不能用although, scientist前不用冠词) (2)“动词＋as＋主语＋其他”构成让步状语从句。 Struggle as he might, he was not able to get out.(不能用although) (3)形容词＋as＋主语＋其他。 Crazy though/as his ideas may sound, some people think there is something in them.(不能用although) (4)副词＋as＋主语＋谓语。 Much as I have traveled, I have never seen anyone who's as capable as John.(不能用although) 2．表示“不管……还是……”用whether...or...来引导让步状语从句。 Whether you like the job or not, you have to do it right now. ◆拓展 其他形式的让步状语从句 让步状语从句还可以由下列的词来引导： no matter how/what/who/when/where...这几个短语的意思是“不论怎样(什么，谁，什么时候，什么地方)”，相当于however, whatever, whoever, whenever, wherever...。 no matter how＋形容词或副词＋主语＋谓语＝however＋形容词或副词＋主语＋谓语，表示“无论……”。 We will solve the problem, no matter how hard it is.＝We will solve the problem, however hard it is. ◆点拨 用although, though，还是as，关键是要看句子结构：是正常语序还是倒装语序。 典例　(新课标卷，22)Try ________ she might, Sue couldn't get the door open. A．if

　　B．when C．since

　　D．as 解析：D　本题考查连词的用法。句意：尽管苏尝试了，但她还是打不开门。根据句子结构可知，本题考查as引导的让步状语从句，要用倒装语序。其结构为：动词/名词/形容词/副词＋as＋主语＋谓语，故D项正确。 【2024浙江卷】17. Ellen was a painter of birds and of nature, _____, for some reason, had withdrawn from all human society. A. which B. who C. where D. whom 【考点】定语从句 【答案】B 【解析】who引导非限定性定语从句，在从句中做主语，修饰先行词Ellen（人名）。Which修行先行词是物的定语从句；whom修饰先行词为人，且在从句中做宾语；where修饰先行词是地点名词，且在从句中地点状语，均不符合语境，故排除。 【难度】中等 【2024四川卷】13. In our class there are 46 students, _____ half wear glasses. A. in whom

　　B. in them

　　C. of whom

　　D. of them 答案与解析】 C

　　本题考查定语从句。前后两句话之间无连词，故不能用人称代词them而应用关系代词whom引导定语从句；在46个学生当中，表所属，应用of。故答案选C。 【2024全国II】8. That evening, _____ I will tell you more about later, I ended up working very late. A. that

　　B. which

　　C. what

　　D. when 【答案】B 【解析】这里that evening是先行词，其在定语从句中作介词about的宾语，所以用which。句意：以后我将和你谈起的那个晚上，我工作到了很晚。【考点定位】考查非限制性定语从句的关系词。 【2024重庆卷】30.—Coach, can I continue with the training?

　　—Sorry, you can’t ______you haven’t recovered from the knee injury. A. until

　　B. before

　　C. to consider

　　D. unless 【考点】状语从句 【答案】 C 【解析】短语语境表示“抱歉，你不能继续训练因为你膝盖受的伤还没有恢复。”由此可知，空白处后面为原因状语从句，C选项符合题意。因此，正确答案为C选项。 【难度】一般 【2024福建卷】30. It is hard for the Greek government to get over the present difficulties_________ gets more financial support from the European Union. A. if B. unless C. because

　　D. since 【考点】考查从句的连词 【答案】B 【解析】根据句意可知“除非有来自欧洲联盟的更多的经济支持，否则希腊政府很难克服目前的困难”，只能选择unless“除非”才能使句意完整。考查状语从句的连词题事实上非常简单，只要找到句中的关键词，然后从句意上去排除就行了，本题关键词是hard和more financial support。 【难度】中等

　　* * * * * * * * * * * * * * * * * * * * *

　　高考英语二轮复习：定语从句与状语从句课件 定语从句 一、定语从句与并列句的区别 请观察下面三个句子： 1．Wang Hong failed in the College Entrance Examination, ______ disappointed his mother. Z

　　x

　　x

　　k 2．Wang Hong failed in the College Entrance Examination and ______ disappointed his mother. 3．Wang Hong failed in the College Entrance Examination;

　　______ disappointed his mother. 第一句话：句中有逗号，根据句意可知，空白处的内容应该指的是前面整个句子的内容，是对前文信息的补充说明，因此，此句是非限制性定语从句，用关系代词which； Z

　　x

　　x

　　k 第二句话：句中有并列连词and，因此整个句子是一个并列句，所以可以用代词it指代前面句子的内容。 第三句话：句中有分号，这表明整个句子是一个并列句，因此可以用代词it指代前面句子的内容。

　　◆技巧Z

　　x

　　x

　　k 判断是定语从句还是并列句，要注意句中的标点符号和句中的连接词。如果句与句之间有连词或者分号，则是并列句；如果是逗号，且逗号后的内容是对前面某一名词的补充说明，则是非限制性定语从句，应该使用关系词。 二、“介词＋关系代词”引导的定语从句中介词的选择 “介词＋关系代词”引导的定语从句中介词的选择是一个常考点，也是一个难点。请看下面三个句子，填上合适的介词，并从中发现一些规律。 1．He was educated at a local grammar school, ______ which he went on to Cambridge. 2．This is the farm ______ which he worked two years ago. Z

　　x

　　x

　　k 3．In the dark street there was not a single person ______ whom she could turn for help. 第一句话：根据句意可知，他在一所当地的语法学校学习之后去了Cambridge，故介词用after。此句中介词的使用与句子的意义有关。 第二句话：把从句补充完整为he worked two years ago on the farm (“在农场”为“on the farm”)，句中介词的选用取决于先行词的意义，即介词跟先行词的搭配。 第三句话：在黑暗的街道上，没有一个她可以求助的人。“向某人求助”这个短语是“turn to sb. for help”，因此此处用介词to。此句中介词的选用取决于从句中的动词固定搭配。 因此，考生在确定其中的介词时，可从以下三方面入手： 1．句子的意思；2.先行词的意义；3.从句中的动词固定搭配。 ◆技巧 考生不妨采用还原法，把从句补充完整，建立与主句的联系，以便判断这个介词与句中其他部分的关系。 ◆链接 注意way(方式)后接定语从句时的引导词。 先行词是way，当引导词在从句中作状语时，用关系词in which, that或者省略；当引导词在从句中作主语或宾语时，用that/which引导(作宾语时，引导词也可以省略)。比较： The way(that/which) he explained to us was quite simple. (把从句补充完整：he explained the way to us，可以看出引导词在从句中作explained的宾语) The way(that/in which) he explained the sentence was simple.(把从句补充完整：he explained the sentence in the way，可以看出引导词在从句中作状语) 三、引导词as, which的区别 1．引导非限制性定语从句，指代整个主句内容时的区别： (1)表达“正如”之意时，用as，如果仅指代整个主句内容而没有“正如”之意，则用which。 He went abroad, which was unexpected. 他出国了，这让大家感到很意外。 She is a good doctor, as her mother used to be. 她是一个很出色的医生，和她母亲当年一样。 (2)当从句位于主句前面时，只用as。 As is known to everybody, the moon travels round the earth once every month. 2．限制性定语从句中有such, the same时，其后常用as引导定语从句(the same后也可用that，但意义不一样)。 He is such a good teacher as we all love and respect. This is the same pen as I lost. 3．as引导非限制性定语从句时，只能指代整个主句内容，而which既可以指代整个主句内容，又可以指代先行词。 The river, which flows through London, is called the Thames. 这条流经伦敦的河叫泰晤士河。(不用as) 4．as常与从句中的know, see, hear, expect等动词连用，也常用于as often happens, as is often the case(常有的事)等句子中。 He was absent from school, as is often the case. 他缺课了，这是常事。 ◆链接 分隔定语从句 一般情况下，定语从句紧跟先行词，可是有的时候，先行词与定语从句之间插入了另外一些内容，这样就把先行词与定语从句分隔开了，这类定语从句叫分隔定语从句。这类句子应特别注意：不要误把插入部分当先行词。 I was the only person in my office who was invited.(先行词是person而不是office) 典例 (天津卷，10) The days are gone ______ physical strength was all you needed to make a living. A．whenB．that C．where

　　D．which 解析：A。本题考查定语从句的引导词。从句主体结构完整，故排除B、D两项；where指地点，与句意不符；故A项正确，引导的定语从句修饰先行词the days。句意：完全靠体力劳动谋生的日子已一去不复返了。 四、关系代词和关系副词的区别 当先行词为表示时间、地点的词时，引导词用关系代词还是关系副词是定语从句学习中的一个难点。要确定引导词在从句中所作的成分(如果引导词在从句中作状语，则用why, when或where，否则用that或which)，考生可以采用“补全法”，即依据句意把从句补充完整(补上去的部分在从句中所作的成分就是引导词在从句中所作的成分)，这样就可以很容易地判断出引导词在从句中所作的成分。 1．Do you still remember the chicken farm ______ we visited three months ago? 分析：把从句补充完整为“we visited the chicken farm three months ago”，考生据此可以判断出引导词在从句中作宾语，因此填关系代词that/which。 2．In an hour, we can travel to places ______ would have taken our ancestors days to reach. 分析：把从句补充完整为“the places would have taken our ancestors days to reach”，考生据此可以判断出引导词在从句中作主语，因此填关系代词that/which。 3．Some pre－school children go to a day care center, ______ they learn simple games and songs. 分析：把从句补充完整为“in (at) the day care center they learn simple games and songs”，据此可以判断出引导词在从句中作地点状语，因此用where/in(at) which。 ◆技巧 遇到时间和地点，判断成分是关键；主语、宾语用关代，状语才能用关副。(关代：关系代词；关副：关系副词) ◆精析 在考查定语从句时，有时命题人故意在空格处设置一些插入语等干扰信息迷惑考生。解题时，考生可以将其忽略，从而排除干扰。 —Is that the small town you often refer to? —Right, just the one ______ you know I used to work for years. 分析：空白处应填where。此题很容易受you know的影响而误填关系代词。其实you know是插入语，解题时可以将其忽略，简化句子结构：just the one ______ I used to work for years，这样考生就很容易判断出引导词在从句中作地点状语，故用关系副词where。 ◆探究 表示时间、地点的先行词的模糊化。研究高考试题后，考生会发现近几年高考试题中表示时间、地点的先行词有些已经不是一个明显的表示时间、地点的词语，如：period, ten years ago, the street, the museum，而是已经模糊化的词语，如：activity, business, occasion, point, case等。解题时考生要弄清这些词汇在句中的意义，并结合其在从句中所作的成分选用恰当的引导词。 ◆警示 point, situation, case后的定语从句的引导词并非总是由where来引导，只有当引导词在从句中作状语时，才用关系副词where，否则用关系代词。 状语从句 一、连词when, while, as的用法区别 1．下列情况下只能用when (1)作并列连词，意思是“在这时”(at this time)，常用于下列句型： ①be doing...when...某事正在进行，这时发生了另外一件事 We were walking along the river when I heard a cry of help. ②be about to do...when...即将做某事，这时发生了另外一件事 I was just about to leave when I saw him running towards me with a bag in his hand. ③had(not)＋过去分词．..when...某事刚发生，就发生了另外一件事；某件事情还没有持续多长时间，就发生了另外一件事 We had just sat down when someone knocked at the door. We hadn't been asleep for long when we heard a terrible noise. (2)表示“既然”。 How can I help them to understand when they won't listen to me? (3)表示“虽然”，位于句中。 He walks when he could take a taxi. 2．下列情况下只能用while (1)表示对比或比较，意为“然而，可是”。 He likes dancing while his brother likes singing. (2)表示“尽管”，用于句首。 While she is a top student, she has some shortcomings. 3．表示发展、变化的情况时，只能用as As he grew older, he lost interest in everything except gardening. ◆拓展 when, while, as的用法共同点 在说明事情发生的背景时，when, while, as都可以使用。 He broke his leg when/while/ as he was playing football. ◆拓展 表示“当……的时候”，可以使用when，也可以使用while。when从句中的谓语动词可以是延续性的，也可以是非延续性的，而while从句中的动词必须是延续性的。请比较： 1．It was nine o'clock when I got home.(非延续性动词) 2．He was reading a newspaper while he was waiting for a bus.(延续性动词) 二、“It＋be＋时间＋从句”中连词的选择 “It＋be＋时间＋从句”句型是高考考查的热点，其中连词的选择是个难点。突破这个难点的关键是要把握好句意，根据句意的需要选择合适的连词： 1．表示“再过多长时间某事才会发生”，用“It will be＋时间段＋before从句”。 It will be three weeks before we have the next exam. 再过三个星期我们才会进行下次考试。 2．表示“自从……以来有多长时间了”用“It be＋时间段＋since从句”，be动词如果用一般现在时，则从句用一般过去时，如果be动词用一般过去时，则从句用过去完成时。 It is three years since he joined the army. He said it was three years since he had joined the army.

　　3．It be＋时间状语＋that＋其他，构成强调句型，意思是“就是在某一时间发生了某事”。 It was at six o'clock that we got home. 4．It be＋时间点＋when从句，表示“某事发生在什么时间”，it指代时间。 It was six o'clock when we got home. ◆技巧 区分“It be＋时间状语＋that＋其他”(强调句型)和“It be＋时间点＋when从句” 妙招：采用还原法，将it be和that去掉，如果能够还原成一个完整的句子，就是强调句型，否则就不是强调句型。 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

　　* * * * * * * * * * * * * * * * * * * * * 三、几种让步状语从句的用法区别 1．though, although, as引导的让步状语从句的区别 although引导正常语序的让步状语从句；though既可以引导正常语序的让步状语从句，也可以引导倒装语序的让步状语从句；as引导倒装语序的让步状语从句。 Although/ though he has limited technical knowledge, the old worker has a lot of experience. as引导让步状语从句时，要把作表语的形容词、名词，作状语的副词或谓语的一部分提到句首，如果是单数名词作表语，把它提到句首时，其前不用冠词。分为以下几类： (1)“名词＋as＋主语＋其他”构成让步状语从句，单数名词前不加冠词。 Scientist as he is, he is still as modest as before, which always moves all the people who know him.(不能用although, scientist前不用冠词) (2)“动词＋as＋主语＋其他”构成让步状语从句。 Struggle as he might, he was not able to get out.(不能用although) (3)形容词＋as＋主语＋其他。 Crazy though/as his ideas may sound, some people think there is something in them.(不能用although) (4)副词＋as＋主语＋谓语。 Much as I have traveled, I have never seen anyone who's as capable as John.(不能用although) 2．表示“不管……还是……”用whether...or...来引导让步状语从句。 Whether you like the job or not, you have to do it right now. ◆拓展 其他形式的让步状语从句 让步状语从句还可以由下列的词来引导： no matter how/what/who/when/where...这几个短语的意思是“不论怎样(什么，谁，什么时候，什么地方)”，相当于however, whatever, whoever, whenever, wherever...。 no matter how＋形容词或副词＋主语＋谓语＝however＋形容词或副词＋主语＋谓语，表示“无论……”。 We will solve the problem, no matter how hard it is.＝We will solve the problem, however hard it is. ◆点拨 用although, though，还是as，关键是要看句子结构：是正常语序还是倒装语序。 典例　(新课标卷，22)Try ________ she might, Sue couldn't get the door open. A．if

　　B．when C．since

　　D．as 解析：D　本题考查连词的用法。句意：尽管苏尝试了，但她还是打不开门。根据句子结构可知，本题考查as引导的让步状语从句，要用倒装语序。其结构为：动词/名词/形容词/副词＋as＋主语＋谓语，故D项正确。 【2024浙江卷】17. Ellen was a painter of birds and of nature, _____, for some reason, had withdrawn from all human society. A. which B. who C. where D. whom 【考点】定语从句 【答案】B 【解析】who引导非限定性定语从句，在从句中做主语，修饰先行词Ellen（人名）。Which修行先行词是物的定语从句；whom修饰先行词为人，且在从句中做宾语；where修饰先行词是地点名词，且在从句中地点状语，均不符合语境，故排除。 【难度】中等 【2024四川卷】13. In our class there are 46 students, _____ half wear glasses. A. in whom

　　B. in them

　　C. of whom

　　D. of them 答案与解析】 C

　　本题考查定语从句。前后两句话之间无连词，故不能用人称代词them而应用关系代词whom引导定语从句；在46个学生当中，表所属，应用of。故答案选C。 【2024全国II】8. That evening, _____ I will tell you more about later, I ended up working very late. A. that

　　B. which

　　C. what

　　D. when 【答案】B 【解析】这里that evening是先行词，其在定语从句中作介词about的宾语，所以用which。句意：以后我将和你谈起的那个晚上，我工作到了很晚。【考点定位】考查非限制性定语从句的关系词。 【2024重庆卷】30.—Coach, can I continue with the training?

　　—Sorry, you can’t ______you haven’t recovered from the knee injury. A. until

　　B. before

　　C. to consider

　　D. unless 【考点】状语从句 【答案】 C 【解析】短语语境表示“抱歉，你不能继续训练因为你膝盖受的伤还没有恢复。”由此可知，空白处后面为原因状语从句，C选项符合题意。因此，正确答案为C选项。 【难度】一般 【2024福建卷】30. It is hard for the Greek government to get over the present difficulties_________ gets more financial support from the European Union. A. if B. unless C. because

　　D. since 【考点】考查从句的连词 【答案】B 【解析】根据句意可知“除非有来自欧洲联盟的更多的经济支持，否则希腊政府很难克服目前的困难”，只能选择unless“除非”才能使句意完整。考查状语从句的连词题事实上非常简单，只要找到句中的关键词，然后从句意上去排除就行了，本题关键词是hard和more financial support。 【难度】中等

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　　高考英语二轮复习：定语从句与状语从句课件 定语从句 一、定语从句与并列句的区别 请观察下面三个句子： 1．Wang Hong failed in the College Entrance Examination, ______ disappointed his mother. Z

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　　k 2．Wang Hong failed in the College Entrance Examination and ______ disappointed his mother. 3．Wang Hong failed in the College Entrance Examination;

　　______ disappointed his mother. 第一句话：句中有逗号，根据句意可知，空白处的内容应该指的是前面整个句子的内容，是对前文信息的补充说明，因此，此句是非限制性定语从句，用关系代词which； Z

　　x

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　　k 第二句话：句中有并列连词and，因此整个句子是一个并列句，所以可以用代词it指代前面句子的内容。 第三句话：句中有分号，这表明整个句子是一个并列句，因此可以用代词it指代前面句子的内容。

　　◆技巧Z

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　　x

　　k 判断是定语从句还是并列句，要注意句中的标点符号和句中的连接词。如果句与句之间有连词或者分号，则是并列句；如果是逗号，且逗号后的内容是对前面某一名词的补充说明，则是非限制性定语从句，应该使用关系词。 二、“介词＋关系代词”引导的定语从句中介词的选择 “介词＋关系代词”引导的定语从句中介词的选择是一个常考点，也是一个难点。请看下面三个句子，填上合适的介词，并从中发现一些规律。 1．He was educated at a local grammar school, ______ which he went on to Cambridge. 2．This is the farm ______ which he worked two years ago. Z

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　　k 3．In the dark street there was not a single person ______ whom she could turn for help. 第一句话：根据句意可知，他在一所当地的语法学校学习之后去了Cambridge，故介词用after。此句中介词的使用与句子的意义有关。 第二句话：把从句补充完整为he worked two years ago on the farm (“在农场”为“on the farm”)，句中介词的选用取决于先行词的意义，即介词跟先行词的搭配。 第三句话：在黑暗的街道上，没有一个她可以求助的人。“向某人求助”这个短语是“turn to sb. for help”，因此此处用介词to。此句中介词的选用取决于从句中的动词固定搭配。 因此，考生在确定其中的介词时，可从以下三方面入手： 1．句子的意思；2.先行词的意义；3.从句中的动词固定搭配。 ◆技巧 考生不妨采用还原法，把从句补充完整，建立与主句的联系，以便判断这个介词与句中其他部分的关系。 ◆链接 注意way(方式)后接定语从句时的引导词。 先行词是way，当引导词在从句中作状语时，用关系词in which, that或者省略；当引导词在从句中作主语或宾语时，用that/which引导(作宾语时，引导词也可以省略)。比较： The way(that/which) he explained to us was quite simple. (把从句补充完整：he explained the way to us，可以看出引导词在从句中作explained的宾语) The way(that/in which) he explained the sentence was simple.(把从句补充完整：he explained the sentence in the way，可以看出引导词在从句中作状语) 三、引导词as, which的区别 1．引导非限制性定语从句，指代整个主句内容时的区别： (1)表达“正如”之意时，用as，如果仅指代整个主句内容而没有“正如”之意，则用which。 He went abroad, which was unexpected. 他出国了，这让大家感到很意外。 She is a good doctor, as her mother used to be. 她是一个很出色的医生，和她母亲当年一样。 (2)当从句位于主句前面时，只用as。 As is known to everybody, the moon travels round the earth once every month. 2．限制性定语从句中有such, the same时，其后常用as引导定语从句(the same后也可用that，但意义不一样)。 He is such a good teacher as we all love and respect. This is the same pen as I lost. 3．as引导非限制性定语从句时，只能指代整个主句内容，而which既可以指代整个主句内容，又可以指代先行词。 The river, which flows through London, is called the Thames. 这条流经伦敦的河叫泰晤士河。(不用as) 4．as常与从句中的know, see, hear, expect等动词连用，也常用于as often happens, as is often the case(常有的事)等句子中。 He was absent from school, as is often the case. 他缺课了，这是常事。 ◆链接 分隔定语从句 一般情况下，定语从句紧跟先行词，可是有的时候，先行词与定语从句之间插入了另外一些内容，这样就把先行词与定语从句分隔开了，这类定语从句叫分隔定语从句。这类句子应特别注意：不要误把插入部分当先行词。 I was the only person in my office who was invited.(先行词是person而不是office) 典例 (天津卷，10) The days are gone ______ physical strength was all you needed to make a living. A．whenB．that C．where

　　D．which 解析：A。本题考查定语从句的引导词。从句主体结构完整，故排除B、D两项；where指地点，与句意不符；故A项正确，引导的定语从句修饰先行词the days。句意：完全靠体力劳动谋生的日子已一去不复返了。 四、关系代词和关系副词的区别 当先行词为表示时间、地点的词时，引导词用关系代词还是关系副词是定语从句学习中的一个难点。要确定引导词在从句中所作的成分(如果引导词在从句中作状语，则用why, when或where，否则用that或which)，考生可以采用“补全法”，即依据句意把从句补充完整(补上去的部分在从句中所作的成分就是引导词在从句中所作的成分)，这样就可以很容易地判断出引导词在从句中所作的成分。 1．Do you still remember the chicken farm ______ we visited three months ago? 分析：把从句补充完整为“we visited the chicken farm three months ago”，考生据此可以判断出引导词在从句中作宾语，因此填关系代词that/which。 2．In an hour, we can travel to places ______ would have taken our ancestors days to reach. 分析：把从句补充完整为“the places would have taken our ancestors days to reach”，考生据此可以判断出引导词在从句中作主语，因此填关系代词that/which。 3．Some pre－school children go to a day care center, ______ they learn simple games and songs. 分析：把从句补充完整为“in (at) the day care center they learn simple games and songs”，据此可以判断出引导词在从句中作地点状语，因此用where/in(at) which。 ◆技巧 遇到时间和地点，判断成分是关键；主语、宾语用关代，状语才能用关副。(关代：关系代词；关副：关系副词) ◆精析 在考查定语从句时，有时命题人故意在空格处设置一些插入语等干扰信息迷惑考生。解题时，考生可以将其忽略，从而排除干扰。 —Is that the small town you often refer to? —Right, just the one ______ you know I used to work for years. 分析：空白处应填where。此题很容易受you know的影响而误填关系代词。其实you know是插入语，解题时可以将其忽略，简化句子结构：just the one ______ I used to work for years，这样考生就很容易判断出引导词在从句中作地点状语，故用关系副词where。 ◆探究 表示时间、地点的先行词的模糊化。研究高考试题后，考生会发现近几年高考试题中表示时间、地点的先行词有些已经不是一个明显的表示时间、地点的词语，如：period, ten years ago, the street, the museum，而是已经模糊化的词语，如：activity, business, occasion, point, case等。解题时考生要弄清这些词汇在句中的意义，并结合其在从句中所作的成分选用恰当的引导词。 ◆警示 point, situation, case后的定语从句的引导词并非总是由where来引导，只有当引导词在从句中作状语时，才用关系副词where，否则用关系代词。 状语从句 一、连词when, while, as的用法区别 1．下列情况下只能用when (1)作并列连词，意思是“在这时”(at this time)，常用于下列句型： ①be doing...when...某事正在进行，这时发生了另外一件事 We were walking along the river when I heard a cry of help. ②be about to do...when...即将做某事，这时发生了另外一件事 I was just about to leave when I saw him running towards me with a bag in his hand. ③had(not)＋过去分词．..when...某事刚发生，就发生了另外一件事；某件事情还没有持续多长时间，就发生了另外一件事 We had just sat down when someone knocked at the door. We hadn't been asleep for long when we heard a terrible noise. (2)表示“既然”。 How can I help them to understand when they won't listen to me? (3)表示“虽然”，位于句中。 He walks when he could take a taxi. 2．下列情况下只能用while (1)表示对比或比较，意为“然而，可是”。 He likes dancing while his brother likes singing. (2)表示“尽管”，用于句首。 While she is a top student, she has some shortcomings. 3．表示发展、变化的情况时，只能用as As he grew older, he lost interest in everything except gardening. ◆拓展 when, while, as的用法共同点 在说明事情发生的背景时，when, while, as都可以使用。 He broke his leg when/while/ as he was playing football. ◆拓展 表示“当……的时候”，可以使用when，也可以使用while。when从句中的谓语动词可以是延续性的，也可以是非延续性的，而while从句中的动词必须是延续性的。请比较： 1．It was nine o'clock when I got home.(非延续性动词) 2．He was reading a newspaper while he was waiting for a bus.(延续性动词) 二、“It＋be＋时间＋从句”中连词的选择 “It＋be＋时间＋从句”句型是高考考查的热点，其中连词的选择是个难点。突破这个难点的关键是要把握好句意，根据句意的需要选择合适的连词： 1．表示“再过多长时间某事才会发生”，用“It will be＋时间段＋before从句”。 It will be three weeks before we have the next exam. 再过三个星期我们才会进行下次考试。 2．表示“自从……以来有多长时间了”用“It be＋时间段＋since从句”，be动词如果用一般现在时，则从句用一般过去时，如果be动词用一般过去时，则从句用过去完成时。 It is three years since he joined the army. He said it was three years since he had joined the army.

　　3．It be＋时间状语＋that＋其他，构成强调句型，意思是“就是在某一时间发生了某事”。 It was at six o'clock that we got home. 4．It be＋时间点＋when从句，表示“某事发生在什么时间”，it指代时间。 It was six o'clock when we got home. ◆技巧 区分“It be＋时间状语＋that＋其他”(强调句型)和“It be＋时间点＋when从句” 妙招：采用还原法，将it be和that去掉，如果能够还原成一个完整的句子，就是强调句型，否则就不是强调句型。 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *