专题04. 谓语动词-2025年新高考英语语法知识通关必备及母题对点精练

2025年新高考英语语法知识通关必备及母题对点精练 专题04. 谓语动词 核心考点思维导图 核心考点讲练 核心考点1. 动词的分类 动词可分为行为动词、系动词、助动词及情态动词四类。 （1）行为动词是表示具体动作的动词，又称实义动词，可分为及物动词(vt.)和不及物动词(vi.)。及物动词后可直接跟宾语, 如I love you.；不及物动词后不能直接跟宾语，接宾语必须用介词连接。The accident happened last night. I arrived at the air port. （2）系动词是联系主语和表语的动词，分类如下： ①Be类系动词:am;is;are;was;were;will be;have/has been: He is an teacher and he is strict with his students. ②感官类系动词：look;sound;taste;smell;feel: This kind of cloth feels very soft. ③变化类系动词：become /grow(old)/turn(red)/get(angry)/go(bad)/come(true)/fall(ill): His face turned red. ④保持类系动词：keep/stay/remain: The weather remains cold.   ⑤表象类系动词：seem/appear/look: He seems happy. ⑥终止类系动词：turn out(结果是...);prove(证明是...) (3)助动词不能单独使用必须和行为动词或系动词连用，帮助其构成一定的时态、疑问/否定/强调或被动语态： ①Be类主动动词（be/am/is/are/was/were）：和现在分词doing连用构成进行时态/和过去分词done连用构成被动语态：I am reading a book. The book is read by me. ②Do类助动词（do/does/did）:在一般现在时或一般过去时中构成否定、疑问、强调: Do you love me? I don’t love you. I do love you. ③Have类助动词（have/has/had）：和过去分词done连用构成完成时态: I have been here for many years. ④Will助动词（will/would/shall）：和动词原形连用构成将来时态: I will/shall help you (4)情态动词也不能单独使用,必须和行为动词或系动词原型连用，表达一定的语气或情感态度，包括can(could)/must/should/have to（had to）/had better/ought to等。 核心考点2. 时态 时态包含时间和状态两个维度，时间包括现在、过去、将来、过去将来；状态包括一般、进行、完成、完成进行，因此英语时态排列组合共16种，常用常考的为10种，如下图所示： 一般时 1． 一般现在时 形式：do/does; am/is/are (1)常常表示人的习惯或经常性发生的动作。常用的时间状语有always，usually，often，sometimes，every day等。 I usually do my homework in the evening every day.我通常每天晚上做作业。 (2)表示客观事实、真理、格言或者警句等。 Practice makes perfect.熟能生巧。 (3)在时间、条件等状语从句中常用一般现在时代替一般将来时。 They’ll stand by you even if you don’t succeed. 即使你不成功，他们也会支持你。 2． 一般过去时 形式：did; was/were (1)表示过去某个时间发生的动作或存在的状态，常与yesterday，last year，three years ago，the other day等时间状语连用。 He arrived at school at 9∶00 am yesterday. 他昨天上午九点到学校。 (2)根据上下文或主从句提示。 I didn’t pass the exam，which made my parents very angry. 我没有通过考试，这让我父母很生气。 3． 一般将来时 形式：will do; will be 表示将来的动作或状态，常用will/shall＋动词原形或者is/am/are going to do，常与表示将来的时间状语tomorrow，next week等连用。 It is said that he will retire next month. 据说他将于下个月卸任。 4. 过去将来时 形式：would do; would be (1)表示从过去的某一时间来看将来要发生的动作或存在的状态。过去将来时常用于宾语从句和间接引语中。 She said she would retire the next year. 她说她明年就退休了。 I wondered what my son would say the next moment.我想知道儿子紧接着会说什么。 (2)三种表示过去将来时的特殊结构： was/were going to＋动词原形；was/were to＋动词原形；was/were about to＋动词原形。 He told me he was to get married the next week.他告诉我他下周结婚。 She was about to say something more，and then checked herself. 她还想说几句，接着又克制住了自己。 进行时 1. 现在进行时 形式：am/is/are doing (1)表示说话时正在进行或发生的动作，也可表示现阶段正在进行的动作或存在的状态。 He is playing basketball on the playground. 他正在操场上打篮球。 (2)某些表示位置移动的动词，如go，come，leave，arrive，start，move等可用现在进行时表示即将发生或计划要做的动作。 John as well as his sister is setting off for Tokyo tomorrow morning. 约翰和姐姐明天早上要动身去东京。 (3)与always，often，constantly等频度副词连用，表示经常反复的行为或某种感情色彩。感情色彩可褒可贬。 The girl is always talking aloud in public. 这个女孩总是在公共场合大声说话。 2. 过去进行时 形式：was/were doing (1)表示过去某一时刻正在发生的动作或过去某一个阶段内一直在进行的动作。 Mrs Green was preparing lunch at eleven this morning.格林太太今天上午11点正准备午餐。 (2)表示动作在另一个过去的动作发生时正在进行，常与when，while引导的时间状语从句连用。 The teacher came in while the boy was reading a novel.那个男孩正在读小说时老师进来了。 3. 将来进行时 形式：will be doing 表示将来某一时刻或某一段时间里正在进行的动作，常与一些标志性的时间状语连用。 Don’t phone me between 5 and 6.We’ll be having dinner then. 五点至六点之间不要给我打电话，那时我们在吃饭。 完成时 1. 现在完成时 形式：have/has done; have/has been (1)表示动作或过程发生在说话之前某个没有明确说出的过去时间，但现在已经完成，且结果仍对现在有影响。 —I’m sorry，but I don’t quite follow you.Did you say you wanted to return on September 20? —Sorry，I haven’t made myself clear.We want to return on October 20. ——对不起，我没完全明白你的话。你是说你们打算9月20号回来吗？ ——对不起，我没有表达清楚。我们打算10月20号回来。 (2)表示一个动作从过去开始，一直延续到现在，可能还要继续下去。 His first novel has received good reviews since it came out last month. 他的第一部小说自上个月出版以来获得了许多好评。 (3)考查现在完成时，往往有较为明显的时间状语。如already，just，yet，since+过去的时间或一般过去时句子，for＋时间段，up to now，until now，so far，by now, ever since，recently，lately，in/over/during the past/last few months/years，over the years等。 I have learned more than two hundred English words in the past three hours. 在过去的3小时里我已经学了200多个英语单词了。 (4)下列句型中常用现在完成时。 It has been＋一段时间＋since从句 This/That/It is the first/second...time that＋现在完成时 This/That/It is the best/finest/most interesting...＋名词＋that＋现在完成时 This is the first time that I have made a speech.这是我第一次做演讲。 It is the most interesting novel that I have ever read.这是我所读过的最有趣的小说。 2. 过去完成时 形式：had done/had been (1)表示在过去某一时间以前已经完成的动作。常见的时间状语有...before/earlier, by/by the end of/by the time/until/before后接表示过去某一时间的短语或从句。 I had put away my cellphone before my father came back. 在我爸爸回来之前我已经把我的手机收起来了。 (2)在hardly/scarcely...when...，no sooner...than...等表示“一……就……”的句式中，主句常用过去完成时。当hardly，scarcely，no sooner置于句首时，主句要用部分倒装。 No sooner had they rushed out of the house than it burnt down. 他们刚从房子里冲出来房子就烧塌了。 (3)动词hope，expect，mean，intend，want，suppose的过去完成时表示过去未曾实现的愿望或意图。 I had hoped to go home from work ahead of time.我本希望提前下班回家。(但未能如愿) 3. 现在完成进行时 形式：have/has been doing (1)常用来表示开始于过去某个时间，一直延续到现在并且会继续进行下去的动作。 All these years they have been contributing articles to our magazine. 这些年来，他们一直向我们杂志投稿。 (2)表示到目前为止的一段时间里一直在反复进行的动作。 We have been seeing each other quite a lot recently.最近我们常常见面。 动词变单数第三人称，过去式/过去分词和现在分词规则 形式 变化规则 构成方法 例词 单数第三人称★ 一般情况 直接加­s mean(意味着；意思是)→means(2020) ；come→comes(2017) 以­ch，­sh，­s，­x结尾 加­es teach→teaches ； mix(混合)→mixes 以­o结尾 加­es do→ does; go→goes 以“辅音字母＋y”结尾 变y 为i加­es carry(携带；搬运)→carries (2020)　 cry—cries 过去式/ 过去分词★ 一般情况 直接加­ed touch→touched (2020) start→started (2018)　 以不发音e结尾 直接加­d hire→hired (2021)　 decide→decided 以重读闭音节结尾，末尾只有一个辅音字母 双写辅音字母加­ed admit→admitted (2020) prefer→preferred 以“辅音字母＋y”结尾 变y为i加­ed carry→ carried (2020) try→ tried 现在 分词★ 直：一般情况 直接加­ing visit→visiting say→saying 去：以不发音e结尾 去e加­ing come→coming(2020) write→writing 双：以重读闭音节结尾，末尾只有一个辅音字母 双写辅音字母加­ing cut→cutting　 run→running 特：特殊情况 特殊记忆 lie(躺；说谎)→lying; die(死)→dying; tie(拴)→tying 对点精练 语法填空 1. (2024全国I卷)Further, the Silk Route Garden around the greenhouse __________(walk) visitors through a journey influenced by the ancient Silk Road, by which silk as well as many plant species came to Britain for the first time. 2. (2024浙江1月首考)Over the last two years, some supermarkets __________(start) selling chicken or salad in packs designed with two halves containing separate portions (份). 3. (2023全国乙卷)The remarkable development of this city, which is consciously designed to protect the past while stepping into the modern world, __________(mean) there is always something new to discover here, and I could be photographing Beijing for the next 50 years. 4. (2023全国II卷) As a little girl, I __________ (wish) to be a zookeeper when I grew up. 5. (2022全国甲卷)In the last five years, Cao __________ (walk) through 34 countries in six continents, and in 2016, he reached the top of Kilimanjaro, Africa's highest mountain. 6. (2022全国乙卷)To celebrate the festival, a number of events took place at the Chinese Businessman Museum in Beijing on Thursday. The chairman of the China Culture Promotion Society __________ （address）the opening ceremony. 7. (2021全国甲卷)We __________ (hire) our bikes from the rental place at the South Gate. My bike was old and shaky but did the job. 8. (2020全国甲卷) “This really excites scientists,” Carle Pieters, a scientist at Brown University, says,“because it ___________(mean) we have the chance to obtain information about how the moon ____________ (construct).” 9. (2020全国Ⅱ卷) This is why decorating with plants, fruits and flowers _________ (carry) special significance. 10. (2020全国Ⅲ卷) When he asked the villagers on the banks of the river where he could find the legendary (传奇的) artist, they smiled and _________ (point) down the river. 11. (2020浙江卷)By about 6000 BC, people __________ (discover)the best crops to grow and animals to raise. 12. (2019全国Ⅰ卷) In recent years some Inuit people in Nunavut ________________(report) increases in bear sightings around human settlements. 13. (2019全国Ⅱ卷)Picking up her “Lifetime Achievement” award, proud Irene __________ (declare) she had no plans to retire from her 36-year-old business. Irene said… 14. (2019全国Ⅱ卷)Irene said, “I don’t see any reason to give up work. I love coming here and seeing my family and all the friends I ___________(make) over the years. 15. (2019全国Ⅲ卷)Our hosts shared many of their experiences and _____________ (recommend) wonderful places to eat, shop, and visit. 16. (2018全国Ⅱ卷) Since 2011, the country ___________ (grow) more corn than rice. Corn production has jumped nearly 125 percent over the past 25 years. 17. (2018全国Ⅱ卷) The Chinese Ministry of Agriculture finds that between 2005—when the government_________(start) a soil-testing program that gives specific fertilizer recommendations to farmers — and 2011, fertilizer use dropped by 7.7 million tons. 18. (2018全国Ⅲ卷) When the gorillas and I frightened each other, I was just glad to find them alive. True to a gorilla’s unaggressive nature, the huge animal ________ (mean) me no real harm. 19. (2015全国I卷)It was raining lightly when I____________(arrive) in Yangshuo just before dawn. But I didn’t care. 20. Jianzi, a game that __________(date) back to the Han Dynasty, is surprisingly simple. 答案速对 1. walks 2. have started 3. means 4. wished 5. has walked 6. addressed 7. hired 8. means; is constructed 9. carries 10. pointed 11. had discovered 12. have reported 13. decleared 14. have made 15. recommended 16. has grown 17. started 18. meant 19. arrived 20. dates 核心考点3. 语态 英语的语态分为主动语态和被动语态。常考的被动语态形式及用法如下： 序号 常用被动语态 构成 序号 常用被动语态 构成 1 一般现在时 am/is/are done 6 过去进行时 was/were being done 2 一般过去时 was/were done 7 现在完成时 have/has been done 3 一般将来时 shall/will be done 8 过去完成时 had been done 4 过去将来时 should/would be done 9 将来完成时 will/would have been done 5 现在进行时 am/is/are being done 10 含有情态动词的 can/must/should/may be done 注意 事项 汉语有一类句子不出现主语，在英语中一般可用被动结构表示。如： It is believed that…           It is generally considered that…        It is said that… It is well known that…      It must be pointed out that…            It is supposed that… It is reported that…           It must be admitted that…                It is hoped that… （1）系动词没有被动形式，但有些表示感受、感官的连系动词feel，sound，taste，look, feel等在主系表结构中常以主动形式表示被动意义：The dish tastes delicious. / Water feels very cold. （2）当cut，sell，read，write，fill，cook，lock，wash，drive，keep等词带状语修饰语时：The clothes washes well. / The book sells well. （3）break out、take place、shut off、turn off、work out等动词词组表示“发生、关闭、制定”等意思时； （4）want，require，need后面的动名词用主动表示被动含义：Thewindow wants/needs/requires repairing.      （5）be worth doing用主动形式表示被动含义：The book is worth reading twice. （6）在“be + ”形容词 + to do”中，不定式的逻辑宾语是句子的主语，用主动代被动。 另外：be to blame(受谴责)，be to rent（出租）也用主动形式表被动。  （1）所有的不及物动词或不及物动词词组不能用于被动语态。 （2）表示状态的谓语动词，如：last、hold、benefit、contain、equal、fit等。 （3）表示归属的动词，如have、own、belong to等。 （4）表示＂希望、意图＂的动词，如：wish、want、hope、like、love、hate等。 （5）宾语是反身代词或相互代词时谓语动词用主动语态，不能用被动语态。 熟记下面词或短语没有被动态： leave, enter, reach, become, benefit, cost, equal, contain, last, lack, fit, fail, have, appear, happen, occur, belong to, take place, break out, come about, agree with, keep up with, consist of, have on, lose heart等 “get＋过去分词”式被动语态 ：在口语和非正式的语体中，常用“get＋过去分词”表示被动语态，其中get相当于be动词，起助动词的作用。这种形式一般用来谈论突然发生的事，通常只表示动作，不表示状态。 Some glasses got broken when we were moving. 我们搬家时有些玻璃杯被打碎了。 有些相当于及物动词的动词词组，如＂动词＋介词＂，＂动词＋副词＂等，也可以用于被动结构，但要把它们看作一个整体，不能分开。其中的介词或副词也不能省略。 The meeting is to be put off till Friday.(介词off不能遗漏) 对点精练 语法填空 1. (2024甲卷)What should __________(do) with such a beautiful place? 2. (2024全国II卷)Two years later, a six-meter-tall pavilion, inspired by The Peony Pavilion, __________ (build) at the Firs Garden, just ten minutes’ walk from Shakespeare’s birthplace. 3. (2024年浙江卷)However, though it’s nice to get a few cents off a pack of sausages, it would help even more if they could sometimes ________ (offer) in smaller packs. Even the biggest sausage fan doesn’t want to eat them every day. 4. (2024九省联考)Fountain pens __________ (use) in schools long ago and have been regaining popularity lately because they are refillable. 5. (2023全国甲卷)Carson proves that a simple lyric form that has been passed down through the ages can still __________ (employ) today to draw attention to important truths. 6. (2023全国乙卷) Having visited several times over the last 10 years, I __________(amaze) by the co-existence of old and new, and how a city was able to keep such a rich heritage (遗产) while constantly growing. 7. (2022全国1卷) The GPNP__________(design) to reflect the guiding principle of “protecting the authenticity and integrity (完整性) of natural ecosystems, preserving biological diversity, protecting ecological buffer zones, and leaving behind precious natural assets (资产) for future generations”. 8. (2021全国甲卷)It__________ (build) originally to protect the city in the Tang dynasty and has now been completely restored (修复). 9. (2020全国I卷)The parts of a museum open to the public _________(call) galleries or rooms. Often, only a small part of museum’s collection is on display 10. (2020全国Ⅲ卷)The artist was sure he would ____________(choose), but when he presented his masterpiece to the emperor's chief minister, the old man laughed. 11. (2020北京卷)Single-use plastic bags are used at most a few times before they _________ (throw) away. 12. (2019全国Ⅲ卷) When they were free from work, they invited us… They also shared with us… On the last day of our week-long stay, we __________(invite) to attend a private concert on a beautiful farm… 13. (2017全国Ⅰ卷) When fat and salt ____________(remove) from food, the food tastes as if it is missing something. 14. (2017全国II卷) Steam engines_____________ (use) to pull the carriage and it must be fairly unpleasant for the passengers. However, the railways quickly proved to be a great success. 15. (2017全国Ⅲ卷) Sarah ____________(tell) that she could be Britain’s new supermodel, earning a million dollars in the next year. Her father Peter, 44, wants her to give up school to model full-time. 16. (2016全国I卷)So it was a great honour to be invited backstage at the not-for-profit Panda Base, where ticket money helps pay for research. I____________（allow) to get up close to these cute animals at the 600-acre centre. 17. (2016 全国II卷)Truly elegant chopsticks might____________(make) of gold and silver with Chinese characters. 18. Asia and Europe, being two different areas, ___________(link) together by mountains and rivers. 19. Information has been put forward that more middle school graduates ___________ (admit) into universities next year. 20. An incredible tree-house restaurant ___________ (complete) by the end of last month and a large crowd of people went there for meals. 答案速对 1. be done 2. was built 3. be offered 4. was used 5. be employed 6. was amazed 7. is designed 8. was built 9. are called 10. be chosen 11. were thrown 12.were invited 13. are removed 14. were used 15. were told/has been told 16. was allowed 17. be made 18. are linked 19. will be admitted 20. had been completed 核心考点4. 主谓一致原则 主谓一致原则 考点详解 例句 语法一致 1. 以单数名词或代词、动词不定式短语、动名词短语或从句作主语时，谓语动词一般用单数形式；主语为复数时，谓语动词用复数形式。 His father is working on the farm. To study English well is not easy. What he said is very important for us all. Reading in the sun is bad for your eyes. 2. 由连接词and或both …… and连接起来的合成主语后面，要用复数形式的谓语动词。 The boy and the girl were surprised when they heard the news. Both she and he are Young Pioneers. 3. 主语为单数名词或代词，尽管后面跟有with，together with，except，but，like，as well as，rather than，more than，no less than， besides，including等引起的短语，谓语动词仍用单数形式；若主语为复数，谓语用复数形式。 Mr. Green，together with his wife and children，has come to China. Nobody but Jim and Mike was on the playground. 4. either，neither，each，every 或no +单数名词和由some，any，no，every构成的复合不定代词，都作单数看待。 Each of us has a new book. Everything around us is matter. 5. 在定语从句中，关系代词that，who， which等作主语时，其谓语动词的数应与句中先行词的数一致。 He is one of my friends who are working hard. He is the only one of my friends who is working hard. 6. 如果集体名词指的是整个集体，它的谓语动词用单数；如果它指集体的成员，其谓语动词就用复数形式。 这些词有family, class, crowd, committee, population, audience等。 Class Four is on the third floor. Class Four are unable to agree upon a monitor. 注：people，police，cattle等名词一般都用作复数。如：The police are looking for the lost child. 7. 由“a lot of，lots of，plenty of，the rest of，the majority of +名词”构成的短语以及由“分数或百分数+名词”构成的短语作主语，其谓语动词的数要根据短语中后面名词的数而定。 There are a lot of people in the classroom. The rest of the lecture is wonderful. 50% of the students in our class are girls. 注：a number of 与the number of的区别 8. 在倒装句中，谓语动词的数应与其后的主语一致。 There comes the bus. On the wall are many pictures. Such is the result. Such are the facts. 意义一致 1. what， who， which， any， more， all等代词可以是单数，也可是复数，主要靠意思来决定。 Which is your bag？ Which are your bags？ All is going well. All have gone to Beijing. 2. 表示“时间、重量、长度、价值”等的名词的复数作主语时，谓语动词通常用单数形式，这是由于作主语的名词在概念上是一个整体。 Thirty minutes is enough for the work. Ten miles is too long. 3. 若主语是书名、片名、格言、剧名、报名、国名等的复数形式，其谓语动词通常用单数形式。 “The Arabian Nights” is an interesting story-book. 4. 表数量的短语“one and a half”后接复数名词作主语时，其谓语动词可用单数形式。 One and a half apples is left on the table. 5. 算式中表示数目（字）的主语通常作单数看待，其谓语动词采用单数形式。 Twelve plus eight is twenty. Fifty-six divided by eight is seven. 6. 一些学科名词是以 –ics 结尾，如：mathematics，politics，physics 以及news， works等，都属于形式上是复数的名词，实际意义为单数名词，它们作主语时，其谓语动词要用单数形式。 The paper works was built in 1990. I think physics isn‘t easy to study. 7. trousers， glasses， clothes， shoes，jeans 等词作主语时，谓语用复数，但如果这些名词前有a（the） pair of等量词修饰时，谓语动词用单数。 My glasses are broken. The pair of shoes under the bed is his.  8. “定冠词the + 形容词或分词”，表示某一类人时，动词用复数。 The old are taken good care of. 9. a (large) quantity of 修饰可数或不可数名词，作主语时，谓语动词用单数。 A large quantity of people is needed here. 注意：quantities一般用复数。 Quantities of food (nuts) were on the table. 10. a great deal of, a large amount of 修饰不可数名词， 作主语时， 谓语动词通常用单数；large amounts of 修饰不可数名词， 作主语时，谓语动词通常用复数。 A large amount of (A great deal of) damage was done in a very short time. Large amounts of money were spent on the bridge. 就近原则 1. 当两个主语由either … or， neither … nor，whether … or …，not only …but also连接时，谓语动词和邻近的主语一致。 Either the teacher or the students are our friends. Neither they nor he is wholly right. 2. there be句型的be动词单复数取决于其后的主语。如果其后是由and连接的两个主语，则应与靠近的那个主语保持一致。 There are two chairs and a desk in the room. Here引导的句子用法同上。 如：Here is a map and a handbook for you. 对点精练 语法填空 1. (2024甲卷)They __________(be) part of a 15-member exploring party that had spent almost five awesome weeks in witness of the natural beauties there. 2. (2024II卷)“Some of the things that Tang was writing about __________ (be) also Shakespeare’s concerns. 3. (2024九省联考)He feels that neat handwriting __________ (be) still an important skill, so he has his students write not only by hand but also with old fashioned fountain pens. 4. (2022全国1卷) The plan will extend protection to a significant number of areas that__________(be) previously unprotected, bringing many of the existing protected areas for giant pandas under one authority to increase effectiveness and reduce inconsistencies in management. 5. (2021全国1卷) You can’t help wondering how hard it          (be)for the people then to put all those rocks into place. 6. (2020天津)The number of medical schools reached 18 in the early 1990s and ______ (remain)around that level ever since. 7. (2019全国Ⅰ卷·70) Of the nineteen recognized polar bear subpopulations, three are declining, six ____________(be) stable, one is increasing, and nine lack enough data. 8. (2019江苏卷)The musician along with his band members___________(give)ten performances in the last three months. 9. (2018全国Ⅰ卷) While running regularly can’t make you live forever, the review says it ____ (be) more effective at lengthening life than walking, cycling or swimming. 10. （2017天津卷）Nowadays, cycling, along with swimming, ____________(regard) as one of the best activities. 11. (2016全国II卷)Leaving the less important things until tomorrow____________(be) often acceptable. 12. (2016全国III卷)Confucius believed knives would remind people of killings and____________(be) too violent for use at the table. 13. Such poets as Shakespeare ________ (be) widely read, of whose works, however, some are difficult to understand.  14. There ________(be) a dramatic rise in the number of extreme weather events over the past 20 years. 15. China____________(witness) great advances in space exploration in recent years. 16. More than two thirds of the surface of the earth ____________ (be) covered by water. 17. Many a book about Africa____________ (write) by Mary last year but I don’t know whether she has finished them. 18. Large amounts of money ____________(spend) on the project so far. 19. They are putting too much carbon dioxide into the atmosphere, which __________( prevent) heat from escaping from the earth into space. 20. This kind of shoes ________(sell) well. 答案速对 1. were 2. were 3. is 4. were 5. was 6. has remained 7. are 8. has been given 9. is 10. is regarded 11. is 12. were 13. are 14. has been 15. has witnessed 16. is 17. was written 18. have been spent 19. prevents 20. sells 原创精品资源学科网独家享有版权，侵权必究！ 学科网（北京）股份有限公司 $$