跟着课文学语法丨外研版·选择性必修三

Unit 1 Face values 选择性必修 主语从句 一、主语从句的概念 主语从句在复合句中充当主语，它可以位于句首，也可以借助形式主语t,将真正的主语从句后置。其 作用是使句子结构更加平衡，避免头重脚轻。 1.从属连词 that(无词义，在从句中不充当成分，但不可省略)、whether(是否)。 That he passed the exam made us all happy. 他通过了考试，这让我们都很高兴。(that引导主语从句，在从句中不做成分，仅起引导作用)》 Whether he will come or not is still unknown.他是否会来仍然未知。(whether引导主语从句，表“是 否”) 2.连接代词 what(·的东西/事情)、who(谁)whom(谁，宾格)、whose(谁的)、which(哪一个)。 What he said is very important..他说的话非常重要，(what在从句中作said的宾语) Who will win the game is hard to say..谁将赢得比赛很难说，(who在从句中作主语) 3.连接副词 when(什么时候)、where(在哪里)、why(为什么)、how(如何)。 hen he will arrive is not clear.他什么时候到达还不清楚。(when在从句中作时间状语) How she managed to finish the work in such a short time is a mystery. 她如何在这么短的时间内完成工作是个谜(how在从句中作方式状语) (观察试题) he likes the book is not clear. A.That B.What C.Whether D.Which 答案：C解析：根据句意“他是否喜欢这本书还不清楚”，表示“是否”用whether引导主语从句。 二、主语从句的不同类型及用法 1.由that引导的主语从句 当从句是一个完整的陈述句时，用that引导，that本身无实际意义，在从句中不充当任何成分，但在句首 引导主语从句时不能省略。 That she is a good teacher is known to us all..她是一位好老师，这一点我们都知道。 That the earth moves around the sun is a well-known fact.地球绕着太阳转是一个众所周知的事 实。 2.由连接代词引导的主语从句 连接代词在从句中充当主语、宾语、定语等成分，具有疑问意义。 What we need is more time.我们需要的是更多时间，(what在从句中作need的宾语) Whose book this is remains a puzzle.这是谁的书仍然是个谜，(whose在从句中作book的定语) 跟着课文学语法 外研版（必修+选必修129 3.由连接副词引导的主语从句 连接副词在从句中充当状语，分别表示时间、地点、原因、方式等。 Where we will have the meeting has not been decided yet. 我们将在哪里开会还没有决定，(where在从句中作地点状语) Why he left in a hurry is not clear.他为什么匆忙离开还不清楚。(why在从句中作原因状语) (观察试题) broke the window remains a mystery. A.What B.Who C.That D.Which 答案：B解析：根据句意“谁打破了窗户仍然是个谜”，从句缺少主语，且表示“谁”，用ho引导主语从句。 三、形式主语t的用法 当主语从句较长时，为避免句子结构失衡，常用t作形式主语，将真正的主语从句后置，常见结构有： 1.t+be+形容词(important,.necessary,strange等)+that从句。 It is necessary that we should learn English well..我们学好英语是有必要的。 2.lt+be+名词(a pity,a fact,a wonder等)+that从句。 It is a pity that he didnt come to the party.他没来参加派对，真可惜。 3.t+be+过去分词(said,reported,believed等)+that从句。 It is said that he has gone abroad.据说他已经出国了。 4.t+不及物动词(seem,happen等)+that从句。 It seems that he is very happy.他似乎很开心。 (观察试题) It is reported more new schools will be built in our city next year. A.that B.what C.which D.how 答案：A解析：“It is reported”后接that引导的主语从句，it是形式主语，真正的主语是“that more new schools will be built in our city next year" 四、主语从句在语篇中的应用 It is obvious that our environment is getting worse.What we should do now is to take immediate action.Whether we can save the earth depends on everyones efforts.How we protect the environment is a question that we should think about carefully.That we live a low-carbon life can make a difference. 很明显，我们的环境正在恶化。我们现在应该做的是立即采取行动。我们是否能够拯救地球取决于每 个人的努力。我们如何保护环境是一个我们应该仔细思考的问题。我们过低碳生活能够产生影响。 (观察试题) In the passage,which of the following statements is TRUE according to the use of subject clauses? A.What we should do now is unimportant. B.Whether we can save the earth doesnt depend on anyone. C.How we protect the environment is a significant question. 130语法点精准定位课文 学习事半功倍 D.That we live a low-carbon life makes no difference. 答案：C解析：文中提到“How we protect the environment is a question that we should think about carefully'”,说明如何保护环境是一个重要问题，A、B、D选项与原文中主语从句表达的意思不符。 【总结】 牢记不同引导词(that,whether,.连接代词/副词)的含义和在从句中的成分，根据从句是否缺成分选择 合适的引导词。 掌握主语从句直接位于句首和用形式主语"t"的两种结构，根据句子平衡选择合适的句式。 主语从句作主语时，谓语动词通常用单数形式。 在某些形容词后的主语从句中，谓语动词用"should+动词原形"，should可省略。 在阅读中，通过语篇分析主语从句的实际应用；在写作时，学会用主语从句丰富句子结构和表达逻辑关系。 【单元练习】 1.语法填空（用合适的连接词填空） ①0 he will come to the party tonight is still unknown. ② we need is more money to carry out the project. ③It is a pity she missed the chance to study abroad. ④ the meeting will be held has not been decided yet. ⑤ broke the glass should be responsible for it. 2.短文改错（每句均有一处与主语从句相关的错误，找出并改正） 1 That he was late for school was because he missed the early bus. 2 What did he say at the meeting is very important. 3 It is known to all of us that if he is a good student. 4 Whether will they attend the concert makes no difference. 5 Which team will win the match are still uncertain. 3.语篇填空（在空白处填人适当的连接词或根据提示完成句子） It is clear 1. the Internet has changed our lives greatly.2. we communicate with others,shop,or study,the Internet provides us with great convenience.3. matters most is how we make good use of it.Some people worry 4. too much time spent online may affect our study and health.5. we can balance our online and offline life is a question we should consider.6. (that more and more people are realizing the importance of a healthy Internet usage. 4.阅读理解中的句子分析（分析下列句子中主语从句的连接词及在从句中的成分和作用） 1 Why he suddenly changed his mind remains a secret. 2 What we saw in the museum yesterday left a deep impression on us 5.句子改写（根据要求改写句子） ①He will come back next week.It is certain.(合并为含主语从句的句子，用it作形式主语) ②Did she pass the exam?It is not clear..(合并为含主语从句的句子，用it作形式主语) ③Where will they build the new factory?This is a problem.(改为主语从句) 6.写作应用（根据中文提示，用主语从句完成英语句子） ①他是否会成功还不知道。 is still unknown. 眼着课文学语法 外研版（必修+选必修131 ②我们需要的是更多的时间和精力。 is more time and energy. ③很明显，他在考试中作弊了。 he cheated in the exam. ④谁打破了窗户应该受到惩罚。 should be punished. ⑤她为什么离开这个城市仍然是个谜。 remains a mystery. 【答案】 1.语法填空 ①答案：Whether解析：根据句意“他今晚是否会来参加派对还不知道”，表示“是否”用Whether引导主语从句。 2答案：What解析：“ we need”中缺少宾语，“我们需要的东西”用What引导主语从句，在从句中作宾语。 ③答案：that解析：“It is a pity"后接that引导的主语从句，it是形式主语，that无意义且不充当成分，不可省略。 ④答案：When解析：根据句意“会议什么时候举行还没有决定”，表示时间“什么时候”用When引导主语从句，在从句中 作时间状语。 ⑤答案：Whoever解析：“ broke the glass”中缺少主语，“无论谁打破了玻璃”用Vhoever引导主语从句，相 当于Anyone who。 2.短文改错 ①答案：将because改为that解析：“That he was late for school'”是主语从句，“he missed the early bus”是表语从句， 表语从句解释原因时用that引导，不用because,所以将because改为hat。 ②答案：将did he sayi改为he said解析：主语从句要用陈述语序，所以将“did he say"改为陈述语序“he said”。 ③答案：去掉if解析：“It is known to all of us”后接hat引导的主语从句，从句是陈述句，不需要if,应去掉if。 ④答案：将will they改为they will解析：主语从句要用陈述语序，所以将will they'改为陈述语序they will'"。 ⑤答案：将are改为is解析：“Which team will win the match”是主语从句，主语从句作主语时，谓语动词用单数形式，所 以将are改为is。 3.语篇填空 ①答案：that解析：“It is clear'”后接that引导的主语从句，it是形式主语，that无意义且不充当成分。 2答案：Whether解析：根据“ we communicate with others,shop,or study”可知，此处表示“无论我们是 交流，购物还是学习”，用Whether引导让步状语从句，与or搭配使用。 ③答案：What解析：“matters most'”中缺少主语，“最重要的事情”用What引导主语从句，在从句中作主语。 ④答案：that解析：“Some people worry"后接that引导的宾语从句，that无意义且不充当成分，可省略，但此处为了句子 结构清晰，保留that。 ⑤答案：How解析：根据“ we can balance our online and offline life”可知，此处表示“我们如何平衡线上和 线下生活”，用HOw引导主语从句，在从句中作方式状语。 ⑥答案：It is said解析：“据说”常用“It is said that.”结构，it是形式主语，真正的主语是that从句。 4.阅读理解中的句子分析 ①连接词：Wy成分：在从句中作原因状语作用：引导主语从句，说明“他突然改变主意”的原因是一个秘密，整个主语 从句在句中作主语。 2连接词：What成分：在从句中作sw的宾语作用：引导主语从句，指代“我们在博物馆看到的东西”，整个主语从句在 句中作主语，表明看到的事物给我们留下深刻印象。 5.句子改写 ①答案：It is certain that he will come back next week. ②答案：It is not clear whether she passed the exam. ③答案：Where they will build the new factory is a problem 6.写作应用 ①)答案：Vhether he will succeed ②答案：What we need ③)答案：It is obvious that ④答案：Whoever broke the window⑤答案：Why she left the city 132语法点精准定位课文 学习事半功倍 Unit 2 A life's work 表语从句 一、表语从句的定义与基本结构 表语从句位于系动词（如be,seem,look,remain,become等）之后，用来说明主语的内容、性质、特征 或状态，在句中充当表语成分，是主系表结构句子的重要组成部分。 基本结构：主语+系动词+表语从句 The question is whether we can finish the work on time.问题是我们是否能按时完成工作。 My suggestion is that we should start early.我的建议是我们应该早点出发。 It seems that he has known the truth.似乎他已经知道了真相。 二、表语从句的连接词 1.从属连词 ①that:无实际意义，在从句中不充当任何成分，但引导表语从句时通常不能省略（在口语或非正式文 体中偶尔可省略)。 The fact is that he didnt tell the truth.事实是他设有说实话。 ②whether:.表示“是否”，不充当句子成分，不能用if替换（在表语从句中，if不能引导表语从句）。 The problem is whether they will support us.问题是他们是否会支持我们。 2.连接代词 ①what:在从句中充当主语、宾语或表语，意为“…的东西/事情”。 What he wants is a book.他想要的是一本书。(what在从句中作宾语) ②who:在从句中充当主语或宾语，意为“谁”。 The winner is who has the most knowledge.获胜者是知识最丰富的人.(who在从句中作主语) ③whom:在从句中充当宾语，意为“谁”（宾格）。 The person he talked to is whom I met yesterday. 他与之交谈的人是我昨天遇到的那个人。(whom在从句中作宾语) ④whose:在从句中充当定语，意为“谁的”。 This is whose book it is.这就是这本书是谁的。(whose在从句中作定语) ⑤which:在从句中充当主语、宾语或定语，意为“哪一个”。 The question is which is the best choice.问题是哪一个是最好的选择，(which在从句中作主语) 3.连接副词 ①when:在从句中充当时间状语，意为“什么时候”。 My worry is when we can get there.我担心的是我们什么时候能到那里。 ②where:在从句中充当地点状语，意为“在哪里”。 The place is where we met for the first time.这个地方是我们第一次见面的地方。 ③why:在从句中充当原因状语，意为“为什么”。 Thats why he was late for school.那就是他上学迟到的原因。 眼着课文学语法 外研版（必修+选必修133 ④how:在从句中充当方式状语，意为“如何”。 The problem is how we can solve it.问题是我们如何解决它， (观察试题) The problem is we can get enough money for the project. A.that B.whether C.if D.what 答案：B解析：句意为“问题是我们是否能为这个项目筹集到足够的资金”，表示“是否”，且在表语从句 中不能用if,要用whether。 三、不同类型的表语从句及用法 1.由that引导的表语从句 当从句是一个完整的陈述句，不缺少任何成分时，用that引导表语从句，that起连接作用，无实际意义。 His dream is that he can become a famous doctor.他的梦想是他能成为一名著名的医生。 The news is that our team has won the game.消息是我们队赢得了比赛。 2.由连接代词引导的表语从句 连接代词在从句中充当一定的句子成分，根据其在从句中的功能和向意选择合适的连接代词。 This is what I want to tell you.这就是我想告诉你的事情。(what在从句中作tel的宾语) Who he is doesnt matter..他是谁并不重要，(who在从句中作表语) 3.由连接副词引导的表语从句 连接副词在从句中充当状语，用来补充说明主语的相关信息，如时间、地点、原因、方式等。 Thats where I lived ten years ago.那就是我十年前住的地方(where在从句中作地点状语) This is how she learned English well..这就是她如何学好英语的，(how在从句中作方式状语) (观察试题) The reason for his success is. he worked harder than others. A.why B.that C.because D.what 答案：B解析：“The reason..is that.”为固定句型，意为“…的原因是…”，that引导表语从句。 四、表语从句在语篇中的应用 My life goal is that I can make a difference in the world.What I need to do now is to study hard and gain more knowledge.The key point is how I can balance my study and life.Sometimes,the problem is whether I can keep my enthusiasm.But I believe that as long as I stick to my dream,I will achieve it one day. 我的人生目标是我能在世界上有所作为。我现在需要做的是努力学习，获取更多知识。关键在于我如 何平衡学习和生活。有时，问题在于我是否能保持热情。但我相信只要我坚持梦想，总有一天会实现它。 (观察试题) In the passage,which of the following statements is TRUE about the predicative clauses? A.The writers life goal is what he can make a difference in the world B.How he can balance study and life is not important. C.Whether he can keep his enthusiasm is sometimes a problem D.He doesnt believe he will achieve his dream. 134语法点精准定位课文 学习事半功倍 有时他能否保持热情是个问题，C选项正确；A选项中引导词使用错误：B选项与原文不符；D选项与原文“ believe that as long as|stick to my dream,I will achieve it one day."相悖。 【总结】 牢记表语从句位于系动词之后，构成主系表结构。 区分that(无意义，不充当成分，通常不省略)和whether(表“是否”，不能用if替换)。 根据从句中所缺成分选择合适的连接代词(what,who等)或连接副词(when,where等)。 记住“The reason..is that.”等常见表语从句的固定句型。 在阅读和写作中，能识别表语从句，理解其对主语进行解释、说明的作用。 【单元练习】 1.语法填空（用合适的连接词填空） ①The question is we can get there on time. ②His suggestion is_ _we should start the project immediately ③Thats」 _she didnt come to the party last night.She was busy with work. ④The problem is of these books is the most suitable for us to read. ⑤It looks it is going to rain.Wed better take an umbrella 2.短文改错（每句均有一处与表语从句相关的错误，找出并改正） 1 The reason for his absence is because he was ill.2 My idea is if we should go there by train. 3 Thats what he solved the difficult problem. 4The fact is he didnt tell the truth to us. 5 It seems whether he has known the good news. 3.语篇填空（在空白处填入适当的连接词或根据提示完成句子） My dream job is 1.I can become a doctor and help those in need.The key point is 2. _I can achieve this goal.First,I need to study hard in high school and enter a good medical university.Then,during university,I should learn knowledge and skills well.The most important thing is 3. I can keep my passion for medicine.Sometimes,the challenge is 4._ I can balance study and practice.However,I believe 5.as long as I work hard,I will realize my dream.And thats 6.I always keep working hard. 4.阅读理解中的句子分析（分析下列句子中表语从句的连接词及在从句中的成分和作用） 1 The truth is that he has been working secretly on this project. 2 Thats why he failed in the exam-he didnt study hard enough. 5.句子改写（根据要求改写句子） ①Ne should protect the environment.That is my opinion.(合并为含表语从句的句子) 2 He didnt come to school because he was ill.(用表语从句改写，以The reason.开头) ③The problem is which way we should choose.(改为以It seems.开头，用it作形式主语) 眼着课文学语法 外研版（必修+选必修135 6.写作应用（根据中文提示，用表语从句完成英语句子） ①我的愿望是有一天能环游世界。My wish is ②问题是我们怎样才能提高英语成绩。The problem is ③这就是他如此开心的原因。This is ④他的建议是我们应该多做运动。His suggestion is ⑤看起来他已经完成了工作。It looks 【答案】 1.语法填空 ①)答案：whether解析：句意为“问题是我们是否能按时到达那里”，表示“是否”，且在表语从句中用hether,不能用if, 所以填whether。 ②答案：that解析：we should start the project immediately”是完整的陈述句，不缺成分，用that引导表语从句，起连接 作用，所以填that。 3)答案：why解析：根据“She was busy with work”可知，此处解释“她昨晚没来参加派对"的原因，用why引导表语从 句，所以填Why。 ④答案：which解析：句意为“问题是这些书中哪一本最适合我们阅读”，表示“哪一个”，在从句中作定语修饰books,所 以填which。 ⑤答案：asif解析：“It looks as if..”为固定句型，意为“看起来好像.…”，所以填asif。 2.短文改错 ①答案：将because改为that解析：“The reason...is that..”为固定句型，表语从句解释原因时用that引导，不用 because,所以将because改为that。 ②答案：将if改为whether解析：在表语从句中，表示“是否”只能用whether,不能用if,所以将if改为whether。 ③答案：将what改为how解析：句意为“那就是他如何解决这个难题的”，表示“如何”，在从句中作方式状语，所以将 what改为how。 ④答案：在is后加that解析：“he didnt tell the truth to us”是完整的陈述句，作表语从句时，引导词that一般不可省略， 所以在is后加that。 ⑤答案：将whether i改为that解析：“It seems that..”为固定句型，意为“似乎…”，所以将hetheri改为that 3.语篇填空 ①答案：that解析：“I can become a doctor and help those in need”是完整的陈述句，不缺成分，用that引导表语从句， 所以填that。 ②答案：how解析：根据语境可知，此处表示“我如何实现这个目标”，在从句中作方式状语，所以填how。 ③答案：that解析：“I can keep my passion for medicine'”是完整的陈述句，不缺成分，用that引导表语从句，所以填 that。 ④答案：whether解析：句意为“有时，挑战是我是否能平衡学习和实践”，表示“是否”，在表语从句中用whether,所以填 whether。. ⑤答案：that解析：“as long as I work hard,I will realize my dream”是完整的陈述句，作believe的宾语从句，that可省 略，但此处为了句子结构清晰，保留that。 ⑥答案：why解析：根据语境可知，此处解释“我一直努力学习的原因”，用why引导表语从句，所以填wy。 4.阅读理解中的句子分析 ①连接词：that成分：在从句中不充当任何成分作用：引导表语从句，起连接作用，说明主语“The truth”的具体内容是 “he has been working secretly on this project”。 ②连接词：why成分：在从句中作原因状语作用：引导表语从句，解释主语“That”(指代前文内容)所指情况的原因，即 “he failed in the exam的原因是“he didnt study hard enough”。 5.句子改写 ①答案：My opinion is that we should protect the environment. ②答案：The reason why he didnt come to school is that he was ill.. ③答案：It seems that the problem is which way we should choose. 6.写作应用 ①)答案：that I can travel around the world one day2答案：how we can improve our English grades ③答案：why he is so happy④答案：that we should do more exercise⑤答案：as if he has finished the work 136语法点精准定位课文 学习事半功倍 Unit 4 A glimpse of the future Unit 5 Learning from nature 主谓一致 概述 主谓一致指主语和谓语在人称和数上保持一致，这是英语句子表达准确的关键语法规则。在高中英语 学习中，掌握主谓一致对于阅读理解、写作等都极为重要。它主要遵循语法一致、意义一致和就近一致三个 原则。 一、语法一致原则 语法一致即主语是单数形式，谓语动词用单数形式；主语是复数形式，谓语动词用复数形式。 1.名词作主语 ①通常情况下，可数名词单数作主语，谓语动词用单数；可数名词复数作主语，谓语动词用复数。 The book is very interesting.这本书很有趣。(book是单数，谓语用is) The books are on the desk.书在桌子上，(books是复数，谓语用are) ②不可数名词作主语，谓语动词用单数。 Water is important for our lives.水对我们的生活很重要。(water是不可数名词，谓语用is) ③集体名词作主语时，若表示整体概念，谓语动词用单数；若强调个体成员，谓语动词用复数。常见的集体 名词有family,,team,class,audience,government等。 ly family is a big one.我的家庭是个大家庭。（表示整体，谓语用is) My family are watching TV.我的家人正在看电视。（强调个体，谓语用are) ④单复数同形的名词作主语，要根据其表达的意义来确定谓语动词的形式。常见的单复数同形名词有 sheep,deer,fish,means等。 This sheep is very fat..这只羊很肥。(sheep在此处表示单数意义，谓语用is) These sheep are eating grass.这些羊正在吃草，(sheep在此处表示复数意义，谓语用are) ⑤以-ics结尾的学科名词，如physics,mathematics,.politics等作主语时，谓语动词用单数。但当这些词 表示“学科”以外的其他意义时，谓语动词用复数。 Physics is not an easy subject for some students..物理对-些学生来说不是一门容易的学科。 (表示学科，谓语用is) His politics are rather conservative.他的政治观点相当保守。（表示政治观点，谓语用are) ⑥表示距离、时间、金钱、重量等的复数名词作主语，若将其视为一个整体，谓语动词用单数；若强调数量， 谓语动词用复数。 Ten years is a long time.十年是一段很长的时间。（将ten years视为整体，谓语用is) Ten dollars are enough to buy this book.十美元足够买这本书，（强调十美元这个数量，谓语用are) ⑦“more than one+单数名词”作主语，谓语动词用单数形式；“more+复数名词+than one'”作主语，谓 语动词用复数形式。 More than one student has passed the exam.不止一个学生通过了考试。谓语用has)》 More students than one have been to the Great Wall.不止一个学生去过长城，（谓语用have) ⑧“分数或百分数+of+名词”构成的短语作主语时，谓语动词的单复数取决于of后名词的数。 跟着课文学语法 外研版（必修+选必修137 Three-fourths of the students in our class are boys.(我们班四分之三的学生是男生。of后students 是复数，谓语用are) 60%of the work has been finished.(60%的工作已经完成。of后work是不可数名词，谓语用has) 2.代词作主语 ①代词each,either,neither,,another以及复合不定代词（如something,anything,nothing,everything, someone,anyone,no one,everyone等)作主语时，谓语动词用单数。 Each of them has a new book.他们每个人都有一本新书。(each作主语，谓语用has) Something is wrong with my bike.我的自行车出毛病了，(something作主语，谓语用is) ②关系代词who,that,which等在定语从句中作主语时，谓语动词的数应与先行词的数一致。 The man who is standing there is my teacher.站在那里的那个人是我的老师。 (先行词man是单数，从句谓语用is) The books that are on the shelf are mine.书架上的那些书是我的。 (先行词books是复数，从句谓语用are) ③all,most,none,some等作主语时，谓语动词的形式要根据它们所代替的内容来定。若代替可数名词复 数，谓语动词用复数；若代替不可数名词或可数名词单数，谓语动词用单数。 All of the students are here.所有的学生都在这儿。(al代替students,谓语用are) All of the water has been used up.所有的水都用完了，(all代替water,谓语用has) 3.非谓语动词及从句作主语 ①动词-ig形式短语或不定式短语作主语时，谓语动词通常用单数。 Reading in the sun is bad for your eyes..在阳光下看书对你的眼睛有害，(reading作主语，谓语用is) To learn a foreign language well is not easy.学好一门外语不容易。(to learn作主语，谓语用is, ②名词性从句作主语时，谓语动词通常用单数。但what引导的主语从句，谓语动词的数由其表示的意义 来决定。 hat he said is very important..他说的话很重要，(what引导的从句作主语，谓语用is) What we need are good books.我们需要的是好书。（从句中need的宾语是books,所以谓语用are) (观察试题) The number of students in our school_increasing. A.is B.are C.be D.were 【解析】“the number of+复数名词”表示“…的数量”，作主语时谓语动词用单数，选A。 语篇示例 In our class,the majority of students like sports.Each of them takes an active part in physical activities.The team which represents our class in the competition is well-trained.The knowledge that we gain from books is important,but what really matters is the practical skills we develop. 二、意义一致原则 意义一致原则是指谓语动词的单复数形式取决于主语所表达的意义，而不是其形式。 1.当主语形式上为单数，但意义上为复数时，谓语动词用复数。 138語法点精准定位课文 学习事半功倍