教师辅导讲义
语法 29时间状语从句 一、什么是状语从句 状语就是在一句话中表示该句子的时间、地点、方式、原因、条件等成分。状语从句就是用一个从 句表示状语。状语从句根据它表达的意思不同，可分为时间、地点、原因、目的、结果、条件、方式、比较、让步等九类。 与状语一样，状语从句的位置比较灵活。既可置于主句之前（通常用逗号与主句隔开），也课置于主句之后（不需要用逗号与主句隔开），有时甚至可以置于主句之中。 二、时间状语从句 1. 主句和从句同时发生，这类从句由从属连词when, while, as引导。 He was hungry when he came home. I was crying while everyone was laughing. As I walked out, he walked in. as, when, while, 的区别 ① as强调从句的动作与主句动作同时发生及持续，具有at the same time的意思 他继续往下谈的时候，越来越兴奋。 as还可以表示一边??一边??，强调从句和主句中两个动作交替进行或同步进行。 他们边走边聊。 as还有“ 随着”的含义 随着春天的到来，天气暖和起来。 ② when 强调动作点的特定时间，具有at the time that 的意思 当老师走进来的时候，我们都站起来了。 ③ while 表示较长的期间，具有during the time that 的意思 当我在这的时候，我很安全。 2.主句发生在从句之前，这类从句由从属连词before, until 引导 ,before 意为“ 在---之前” until 在肯定句中意为“直到 --- 为止”，在否定句中意为“直到 --- 才”。从句既可置于主句前，也可置 于主句之后。 回家之前我必须干完所有的活。
状语从句 状语从句用来修饰主句中的动词，副词和形容词的从句叫状语从句。根据其含义状语从句可分为时间状 语从句，地点状语从句，条件状语从句，原因状语从句，结果状语从句，比较状语从句，目的状语从句，让 步状语从句。 1. 时间状语从句 ⑴时间状语从句常用when, as, while, before, after, since, till, until, as soon as 等连词来引导。例如： It was raining hard ( rain hard 下大雨) when got to school yesterday. While he was doing his homework, the telepho ne rang. As he walked along (沿着走) the lake, he sang happily. He had lear ned a little Chin ese before he came to China. After he finished middle school, he went to work in a factory. (2) 在时间状语从句里，通常不用将来时态，用现在时态表示将来的动作或状态。例如： I ' ll ring you up as soon as I get to New York. I will tell him everyth ing whe n he comes back. He won ' t believe it until he sees it with his own eyes. (3) 在带有till或until引导的时间状语从句的主从复合句里，如果主句用肯定式，其含义是一直到……时” 谓语动词只能用延续性动词。如果主句用否定式，其含义是直到……才……”,在…??…以前不……”,谓语动词可用瞬间动词。例如： The young man read till the light went out (熄灭) Let ' s wait until the rain ops. We won' t start until Bob comes. Don' get off (从下来) until the bus stops. 【Till是指直到某一特定事件发生的时候，而在那个时刻之后，该事情或状况仍将持续。Until是指直到某一特定事件发生的时候，而讲话的人在自己心里认为，在那个时刻之后，该事情或该状况将中止 (不怎么可能持续)。固定组合里from morning till night，till/until是不能替换的，】 2. 条件状语从句 (1) 条件状语从句通常由if, unless引导。例如： What shall we do if it snows tomorrow? Don' t leave the buildi ng uni ess I tell you to. (2) 在条件状语从句里，谓语动词通常用现在时态表示将来的动作或状态。例如： I ' ll help you with your English if am free tomorrow. He won ' t be late uni ess he is ill. (3) 祈使句+ and (or)+陈述句”在意思上相当于一个带有条件状语从句的复合句。例如： Hurry up, or you ' ll be late. =If you don ' t hurry up, you ' ll be late. Study hard and you will pass the exam. =If you study hard, you will pass the exam. 3. 原因状语从句
英语让步状语从句用法总结（一） 让步状语从句的用法一（表示“虽然，即使，尽管”） 1. although，though，even though，even if都表示“虽然，即使，尽管”之意，though 和although 语气较弱(其中的though 比although 通俗, 不如although 正式)，even if和even though 带有强调意味而显得语气更强。例如：Although they are poor, they are happy. 虽然他们很穷，但很快乐。天气虽然很冷, 但他没有穿大衣就出去了。即使他们可能不会成功，但他们仍努力尝试。那篇文章虽然很短，但很重要。他好一点了，虽仍未痊愈。即使下雨，她也是走着去工作的。今晚我将去拜访他，即使我只能停留一小会儿。 注意：though 引导的让步状语从句的用法比较特殊，它可以倒装，也可以不倒装，具体用法参见as引导让步状语从句的用法。 2. as引导让步状语从句表示“虽然、即使、尽管”，其引导的让步状语从句必须采用倒装结构，as引导的倒装形式的让步状语从句的基本结构为：形容词/副词/名词(单数可数名词前一般不带冠词，有时也可见单数可数名词前形容词与不定冠词连用、形容词放在不定冠词前)/动词/过去分词＋as＋主语＋谓语的其他部分。注意体会下列典型例句：Great as the author was, he proved a bad model. 这位作者尽管了不起，到头来却成了一个坏榜样。这个故事看似荒唐，却是真的。虽然他很富有，但他并不幸福。倒装时要省去单个名词前的冠词)尽管还是个孩子，他却能分辨黑白。他尽管勇敢，可见到蛇还是发抖。尽管伤势很重，他仍然十分乐观。虽然尽了最大努力，但是他仍然不能搬动那块石头。 ［考题1］We had to wait half an hour ____ we had already booked a table. A. since B. although C. until D. before ［答案］B ［解析］下划线处之后所述的“我们已经预订了一桌”与前面所述的“我们已经不得不等了半个小时”之间语意相反，四个选项中although表示“即便……”，引导让步状语从句最为合适。 ［考题2］____ most of the earth’s surface is covered by water, fresh water is very rare and precious. A. As B. Once C. If D. Although ［答案］D ［解析］句意为：虽然地球表面覆盖着水，但是纯净水仍然很稀有、珍贵。下划线处应引导让步状语从句，填入although最为合适。 ［考题3］____ he has limited technical knowledge, the old worker has a lot of experience. A. Since B. Unless C. As D. Although ［答案］D ［解析］下划线处应引导让步状语从句，填入although最为合适。 ［考题4］Although he is considered a great writer, ____. A. his works are not widely read B. but his works are not widely read C. however his works are not widely read D. still his works are not widely read ［答案］A ［解析］英语不允许在连词although、though引导的让步状语从句之后的主句句首重复使用连词，如果要在复合句中强调某种特别的意义，可以在主句的句首加上yet、still等副词。例如：Although she has a lot of money, (yet/still) she is not happy. 虽然她很有钱，但是她并不快乐。
高一英语必修1 Unit 1 Friendship Part 1. Warming up 1.介词不同，含义有别： be good to sb./sth. 对… 好be good for sb./sth. 对… 有好处 be good at (doing) sth. 擅长，精通be good with sb./sth. 善于应付… 的 eg. She was very good to me when I was ill. Doing morning exercises is good for health. Tim is good at speaking English. He is very good with children. 他对孩子很有一套。 2.add up 合计，把…加起来add up to 合计达到… add to 增加，增添add A to B 把…加进…里面，把…和…相加 eg. Please add these figures up. These figures add up to 900. The bad weather added to our difficulities. Please add some salt to the water. Add three to four and you get seven. ▲ add vt. 补充说（后接that从句或者直接引语） eg. He added that they would return in a week. “And don’t be late,”she added. 3.point n.点，要点，观点，意义，得分v.指着 be on the point of doing sth. when......=be about to do sht. when....正要做某事，这时...... There is no point (in) doing sth. 没有必要（意义）做某事 4. until与not … until until表示动作、状态的持续，强调“一直到……为止”，或强调某个动作或状态一直持续到另一个动作或状态出现之前。常与表示延续性动作的动词连用。 not … until表示“到……为止；直到……才”，常与表示瞬间性动作的动词连用。 eg. He lived with his parents until he graduated from college. The noise of the street didn’t stop until midnight. 5. finish sth./doing sth. 后跟动名词作宾语的动词或短语还有：admit, appreciate, avoid，consider，delay, enjoy，escape, feel like, forgive, get down to, give up, imagine，mind, miss（错过）, practice, suggest, risk，can't stand（不能忍受）, can’t help (忍不住），give up, put off等。 help sb.(to) do sth. There is no way to escape doing the work. 没有办法逃脱做这项工作。 We shall appreciate hearing from you again. 能再次收到你的来信，我们将十分感激。 He put off paying the bills 6. get sth. done 使某事被做( get做使役动词，“使、叫、让”后接复合宾语) eg. When are you going to get your hair cut? I must get my homework finished first before going out to play. He got his foot hurt while playing football. ▲get sb. to do sth. 让某人做某事eg. I will get him to do the work. ▲get sb./sth. doing…使某人或者某物开始…起来eg. Let me try now. I will get the car going. ▲get + n. + adj. 使… 成为某种状态eg. Get everything ready. ★联想：have sth. done 使某事被做 have sb. do sth. 让某人做某事
一地点状语从句 地点状语从句通常由where, wherever 引导。 Where I live there are plenty of trees.我住的地方树很多。 Wherever I am I will be thinking of you. 不管我在哪里我都会想到你。 二. 方式状语从句 方式状语从句通常由as, (just) as…so…, as if, as though引导。 1）as, (just) as…so…引导的方式状语从句通常位于主句后，但在(just) as…so…结构中位于句首，这时as从句带有比喻的含义，意思是"正如…"，"就像"，多用于正式文体，例如：Always do to the others as you would be done by.你希望人家怎样待你，你就要怎样待人。As water is to fish, so air is to man.我们离不开空气，犹如鱼儿离不开水。 Just as we sweep our rooms, so we should sweep backward ideas from our minds. 正如打扫房屋一样，我们也要扫除我们头脑中落后的东西。 2）as if, as though 两者的意义和用法相同，引出的状语从句谓语多用虚拟语气，表示与事实相反，有时也用陈述语气，表示所说情况是事实或实现的可能性较大。汉译常作"仿佛……似的"，"好像……似的"，例如： They pletely ignore these facts as if (as though) they never existed. 他们完全忽略了这些事实，就仿佛它不存在似的。（与事实相反，谓语用虚拟语气。） He looks as if (as though) he had been hit by lighting. 他那样子就像被雷击了似的。（与事实相反，谓语用虚拟语气。） It looks as if the weather may pick up very soon. 看来天气很快就会好起来。（实现的可能性较大，谓语用陈述语气。） 说明：as if / as though也可以引导一个分词短语、不定式短语或无动词短语，例如： He stared at me as if seeing me for first time.他目不转睛地看着我，就像第一次看见我似的。He cleared his throat as if to say something.他清了清嗓子，像要说什么似的。 The waves dashed on the rocks as if in anger.波涛冲击着岩石，好像很愤怒。 三. 原因状语从句 比较：because, since, as和for 1）because语势最强，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或since。 I didn't go, because I was afraid. Since /As the weather is so bad, we have to delay our journey. 2）由because引导的从句如果放在句末，且前面有逗，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。 He is absent today, because / for he is ill. He must be ill, for he is absent today. 四. 目的状语从句 表示目的状语的从句可以由that, so that, in order that, lest, for fear that, in case等词引导，例如：
【英语】初中英语状语从句试题经典 一、初中英语状语从句 1． the journey was tiring，Jeff thought it was worth both the time and the money. A．As B．Since C．Unless D．Although 【答案】D 【解析】 【详解】 句意：虽然旅途很累，杰夫认为时间和金钱都值得。 A. As当……的时候； B. Since 自从； C. Unless除非； D. Although尽管。根据下文Jeff thought it was worth both the time and the money.可知上文是让步状语从句，这里用Although引导。根据题意，故选D。 2．-- Can’t I park my car free here? -- You can, for four hours, __________ you spend over 100 yuan in this supermarket. A．though B．if C．unless 【答案】B 【解析】 【详解】 句意：-我不能把车免费停在这里吗？- 如果你在这家超市花费超过100元，你可以免费停车四个小时。though 虽然；if 如果；unless 除非。这里是形容一种条件，如果消费超过100元，就能免费停车，故选B。 3．My English teacher has taught English she came to the school. A．since B．as C．when D．for 【答案】A 【解析】 【详解】 考查连词辨析，句意：我的英语老师自从来到这个学校就教英语．结合语境推断句意是"我的英语老师自从来到这个学校就教英语．"，此句中的谓语动词用了现在完成时，本题设空处后面的时间状语从句用了一般过去时，所以结合句意用现在完成时的标志词since引导，故选A 4．He made a serious mistake, but he took immediate action to change that ______ it got worse. A．until B．when C．because D．before 【答案】D 【解析】 试题分析：句意：他犯一个严重的错误。但他采取行动来改变它以免变得更糟。A. Until直到；B. When当……时；C. Because因为；D. Before在……之前。在变得更糟之前采取行动改
TheAdverbialClauses 抚宁一中王艳 I.Teachingtopic：TheAdverbialClauses II.Teachingtype：Grammar III.TeachingObjectives: 1Inknowledge： Enhancestudents’proficiencyandaccuracyinusingthe adverbialclauses. StepI ooseonekindoftheclausesandanswerquestionstogetpoints. 1.AdverbialClausesofTime(时间状语从句) 1）Askstudentstodomultiple-choicetoknowthedifferenceamong“when”,“while”and“as”. 2)Askstudentstothinkaboutotherconjunctionsandwritesentencesbythemselves.Thenaskst udentstocorrectmistakesbythemselvesandexplaintheimportantanddifficultpoints. 3)Askstudentstotranslatethreesentencestoknowdifferentmeaningsof“before” 2.AdverbialClausesofConcession(让步状语从句) 1）Askstudentstofillintheblanksaccordingtothepicture. 2)Askstudentstodomultiple-choicetoacquiretheimportantpoints. 3.AdverbialClausesofManner(方式状语从句)
状语从句 一. 单项填空 1. _______ he’s old, he can still carry this heavy bag. A. Though B. Since C. For D. So 2. ---Do you know if he _______ to play basket ball with us? ---I think he will come if he ______ free tomorrow. A. comes; is B. comes; will be C. will come; is D. will come; will be 3. In the zoo if a child _____ into the water and can’t swim, the dolphins may come up ______ him. A. will fall; to help B. falls; to help C. will fall; help D. falls; helping 4. I don’t remember ________ he worked in that city when he was young. A. what B. which C. where D. who 5. We will stay at home if my aunt ________ to visit us tomorrow. A. comes B. come C. will come D. is coming 6. The police asked the children _______ cross the street ________ the traffic lights turned green. A. not; before B. don’t; when C. not to; until D. not; after 7. I was late for class yesterday _______ there was something wrong with my bike. A. when B. that C. until D. because 8. I’ll go swimming with you if I ________ free tomorrow. A. will be B. shall be C. am D. was 9. In the exam, the ________ you are, ______ the _______ mistakes you will make. A. careful; little B. more careful; fewest C. more careful; fewer D. more careful; less 10. Y ou should finish your lessons _______ you go out to play. A. before B. after C. when D. while 11. I hurried _____ I wouldn’t be late for class. A. since B. so that C. as if D. unless 12. When you read the book, you’d better make a mark _______ you hav e any questions. A. which B. that C. where D. though 13. The teacher raised his voice _______ all the students could hear him. A. for B. so that C. because D. in order 14. He took off his coat _______ he felt hot. A. because B. as C. if D. since 15. It is ______ that we’d like to go out for a walk. A. a lovely day B. too lovely a day C. so lovely a day D. such lovely a day 16. Mary had ______ much work to do that she stayed at her office all day. A. such B. so C. too D. very 17. _______ I felt very tired, I tried to finish the work. A. Although B. Because C. As D. As if 18. ______ the day went on, the weather got worse. A. With B. Since C. While D. As
初中英语―条件状语从句 一．条件状语从句的概念 条件状语从句，即在某种条件下，一件事情可能发生。在英语中由连接词if或unless 等引导的状语从句叫做条件状语从句。条件是指某一件事情实现之后（状语从句中），一件事情（主句）才能发生，通常译作“假如，只要，如果”等意思。条件状语从句中，主从句的时态要遵循“主将从现”的原则。即，主句是将来时态时，从句用一般现在时代替将来时态。 二.条件状语从句的引导词 1.If conj . 如果，假如 If you ask him，he will help you．如果你请他帮忙，他会帮你的。 If you fail in the exam，you will let him down． 如果你考试不及格，你会让他失望的。 2.unless conj.除非,若不,除非在……的时候（if ...not...） You will fail to arrive there in time unless you start earlier. 如果你不早点动身,你就不能及时赶到那儿。 Unless it rains, the game will be played.除非下雨,比赛将照常进行。 3.so/as long as conj.只要 You may borrow my book as long as you keep it clean. 只要你保持书的清洁，你就可以把我的书借去。 三．关于条件句的时态，常见的有以下三种情况： 1、条件状语从句的主句是一般将来时，那么从句常常用一般现在时。 When I grow up, I’ll be a nurse and look after patients. 我长大后要当一名护士，照顾病人。 2、如果主句是祈使句，那么从句通常要用一般现在时。 If you want to have a chat ,call me up. 如果你想聊天，打我电话。 3、如果主句是含有情态动词时，根据需要从句多用一般现在时。
英语中六大从句用法总结 从句是指用于复合句中担当某个句子成分的主谓结构。虽说从句自身的句子结构是完整的，但是它不能视为独立的句子，因为它离开了主语就无法独立、完整地表达意思。按其所能表达的意义而言,它相当于一个词或是一个词组. 按从句的句子功能划分（也就是按从句在句子中所担任的成分来划分），从句可分为：主语从句、宾语从句、表语从句、同位语从句、定语从句和状语从句。 1.主语从句 1）主语从句可直接位于主语的位置，如果从句较长，谓语又较短，可用it作形式主语，而将从句放在句末。常见的句型有： *It is a fact\a pity\a question\good news that... *It seems\appears\happened\has turned out that... *It is clear\important\likely\possible that... *It is said\reported\estimated\has been proved that... It is said that comic books create a connection between people of the same generation. It seems that the performance is very useful. 2)what引导的主语从句表示“...的东西时”，一般不用it作形式主语。 What we lack is experience. 3)what,who,when,why,whether等词含有各自的疑问意义，但它们引导的主语从句，都用陈述语序。 How the plan is to be carried out should be discussed again. I did know why I felt like crying. 2.宾语从句 1）宾语从句可位于及物动词、介词和某些形容词后。连词that常可省略。介词后一般接疑问词引导的宾语从句。in that(因为),except that(除了),but that(只是）已构成固定搭配，其他介词后一般不接that引导的宾语从句。 *I promised that I would change the situation. *All this is different from what American young people would say about friendship. *He is certain that watching so much television is not good for children. *This article is well-written except that it is a bit too long. 2)宾语从句后如有宾补，要用形式宾语it来代替，而把宾语从句移至宾补之后。 He has made it clear that he would not change his mind. 3)在think,believe,suppose,expect等动词后的宾语从句中，如果谓语是否定的，一般将否定词移至主句谓语上，宾语从句则变成肯定形式。 He didn't think that the money was well spent. 3.表语从句 表语从句出现在结构为“主语+系动词+表语从句”的句子中。表语从句除可用that,what,when,why,whether,how等引导外，还可由because,as if(though)等引导。that常可省略。如主句主语为reason,只能用that引导表语从句，不可用because.
状语从句的省略形式高考试题汇集 if/ unless 第一组： 1. (2010浙江,8) The experiment shows that proper amount of exercise, if _______ regularly, can improve our health. A. being carried out B. carrying out C. carried out D. to carry out 2. (2001湖南,21) Every evening after dinner, if not _______ from work, I will spend some time walking my dog. A. being tired B. tiring C. tired D. to be tired 3. (2007四川,35) The flowers his friend gave him will die unless _______ every day. A. watered B. watering C. water D. to water 4. (2003上海春,37) Unless ________ to speak, you should remain silent at the conference. A. invited B. inviting C. being invited D. having invited 第二组： 1. (2012陕西,25) All the photographs in this book, _______ stated otherwise, date from the 1950s. A. unless B. until C. once D. if 2. (2009全国II,10) All the dishes in this menu, _______ otherwise stated, will serve two or three people. A. as B. if C. though D. unless 3. (2010山东,28)The school rules state that no child shall be allowed out of the school during the day, _______ accompanied by an adult. A. once B. when C. if D. unless 第三组： 1. (2007全国I,28) We all know that, _______, the situation will get worse. A. not if dealt carefully with B. if not carefully dealt with C. if dealt not carefully with D. not if carefully dealt with 2. (2007陕西,7) Though he started late, Mr. Guo played the piano as well as, if _______, Miss Liu. A. not better than B. not better C. no better than D. no better 3. (1994全国,28) John plays football ________, if not better than, David. A. as well B. as well as C. so well D. so as well 第四组： 1. (2012北京,27) ________ with care, one tin will last for six weeks. A. Use B. Using C. Used D. To use 2. (2012湖南, 23) Time, _______ correctly, is money in the bank. A. to use B. used C. using D. use when 第一组：
初中英语状语从句知识点总结(一） 用来修饰主句中的动词，形容词或副词等而充当状语的从句叫做状语从句。状语从句常用从属连词来引导,与主句连接起来。若置于句末,则前面不加逗号。根据意义和作用，状语从句可分为时间原因条件等几种。下面我们就来分析一下这几种状语从句。 1时间状语从句 时间状语从句常用从属连词wheｎ,aｆtｅｒ，unｔil,as soon as，等来引导。 当主句是祈使句或谓语动词是一般将来时态或情态动词时,其时间状语从句中的谓语动词常用一般现在时态表示将来发生的动作或存在的状态。这就是我们常说的“主将从现”。 如:Ｐlease cａll me ｗheｎ yｏu ｇeｔｔｈere．当你到那时,请给我打个电话。 I ｗill write tｏ you ａs ｓｏｏn as I arrｉｖe in Beｉjing.我一到北京就给你写信。 <温馨提示>siｎce引导时间状语从句表示“自从…以来”，从句中的动词一般表示动作的起点，用过去时;而主句的动作延续的情况则用一般现在时或现在完成时。常用的句型为： It hａs beｅn/is+一段时间+ｓｉnｃe+过去时。 如：I hａs ｂeｅｎ/is three yeａrs since ｗe meｔ laｓt ｔｉｍe.自从我们上次见面,已经三年了。 2条件状语从句 引导条件状语从句的连词或词组有：if(如果),unless(除非),as ｌｏnｇ as(只要）等。如果主句是将来时，条件状语从句也用一般现在时来表示。 如：I will ｓtａy at home ｉf it raiｎs tomorrｏｗ.如果明天下雨,我就待在家。 You can’t learn Englisｈweｌl unｌess you woｒk ｈard． 除非你努力学习，否则是学不好英语的。 <温馨提示>由ｉf引导的条件状语从句，若从句表达的是与现在事实相反的事实,则常用虚拟语气,即用过去时态表示(如果涉及到ｂe动词，一律都用wｅre)。此时,主句则用过去将来时。
状语从句的用法 【真题再现】 1. — Mrs. Li, will you be angry your students don’t obey the rules in class?(2014 山西) — A little. But I will stop them in a friendly way. A. if B. unless C. though 2. jeans were invented over 100 years ago, they're still in fashion today.(2014 江西) A. Because B. If C. Although D. Since 3. The teacher asked me to read aloud all the students could hear me.(2014 滨州) A. so that B. for C. because D. in order to 4. — The air pollution is terrible. (2014 扬州) — It will be worse we take action to protect the environment. A. if B. unless C. until D. when 5. Lin Feng has to work late, she always wears a smile on her face. (2014 南京) A. Because B. If C. Until D. Though 6. In summer milk will quickly go bad it is put into a fridge. (2014 杭州) A. though B. unless C. because D. once 7. I don’t like TV series it’s boring．(2015 青海) A．but B．and C．because 8. Mr. Smith has a habit of taking a shower he has breakfast. (2015 温州) A. though B. before C. because D. since 9．You’d better travel around Nanjing with a local tour guide you want to know more about its culture. (2015 南京) A．unless B．until C．although D．if 10. Pandas are facing danger! The situation won’t change humans stop killing．(2015 南通) A．unless B．though C．if D．after 11. — Jenny, will you leave for the USA now? (2015 常州) — No. It will be two weeks I leave here. A. until B. since C. before D. when 12. my cousin is very young, she can help with the housework.(2015 福州) A. Once; 不填 B. Though; but C. Although; 不填 【答案与解析】 1. A。句意：——李老师，如果你的学生不遵守课堂纪律你会生气吗？——有点儿。但 我会用一种友好的方式去阻止他们。if如果；unless除非；though尽管，引导让步状语从句。 根据句意可知答案为A项。 2. C。句意：尽管牛仔裤在100多年前就被发明出来了，但是它们今天仍然很流行。 because因为；if如果；although尽管；since自从。根据句意可知选择C项。 3. A。句意:老师叫我读大声一点，这样的话，所有的学生都可以听得到。这是一个结果 状语从句，所以排除B、C项；D选项in order to 后面接短语，故选A。 4. B。句意：——空气污染很糟糕。——它将变得更糟糕，除非我们采取行动保护环境。 if如果；unless除非，如果不；until直到；when当……时候。根据语境选B项。