初中人教版七年级英语情态动词
【概念引入】
1）情态动词表示说话人对所做动作的观点或态度。如：需要、可能、意愿、怀疑等。
例如：I must go now. 我现在必须得走了。
2）情态动词一般没有人称和数的变化，但是个别情态动词有时态的变化。
例如：can的过去式是could。
3）情态动词不能单独作谓语，后接动词原形共同做谓语。
例如：I can swim. 我会游泳。
4）常见的情态动词有：can, may, must, have to, should, would等。 5）情态动词一般不止一个意思，它的否定式是在情态动词的后面加not，一般疑问句是将情态动词提到句首。
例如：I can’t speak French. 我不会说法语。
Can you speak English？你会说英语吗？
【用法讲解】
1.can的用法。
1）表能力
We can do our homework by ourselves. 我们可以自己完成作业。
He can swim well. 他游泳很好。
I can play football but I can’t play the piano. 我会踢足球但是我不会弹钢琴。
2）表许可
You can watch TV after supper. 晚饭后你可以看电视。
You can’t play basketball in the street. 你不能在街上打篮球。3）表请求
Can you help me with my math? 你能帮我学数学吗？
Could you lend your book to me? 你能把你的书借给我吗？
注意：could 是can的过去式，但是这里并不表示过去时，而是表示委婉语气。
拓展：can 和be able to的区别
（1）情态动词can只有两种时态形式，现在式can和过去式could，而be able to有多种时态形式。在一般过去时中都表示能够时，
两者可以互换。
例如：Mary can play the piano. （一般现在时）
玛丽会弹钢琴。
She could / was able to play the piano when she was five. （一般过去时）
她五岁时就会弹琴。
She has been able to play it since she was five. （现在完成时）
她自从五岁起就会弹琴了。
（2）用在过去时中，could经常表示能够做某事，事实上不一定去做，而was ?were able to则表示“过去设法做成了某事”。在否定句
中两者可通用。
例如：He could swim across the English Channel. But he didn’
牛津英语七年级（下）期中测试二.笔试部分（120分） I．单项选择（20分） （）21. I don‘t like summer because there is____rain. A. much too B. too many C. too much D. many too （）22. Anna speaks quietly, so____students in our class hear her. A. few B. many C. all D.most （）23. My little brother went to school____it rained heavily. A. but B. although C.if D. because （）24. Which number is the closest to 1? A. 0.9 B. 0.87 C.1.5 D. 1.05 （）25. Thank you very much____me the good idea. A. to tell B. for tell C.for telling D. your telling （）26. Lin Tao and Li Ming____good at schoolwork.. A. is both B. all are C. are all D. are both （）27. Do you enjoy____in China? A. live B. to live C. living D. lives ( ) 28.--______ does your father do morning exercises?—Hardly ever. A. How B. How often C. When D. What time ( ) 29._____is important for us _______sports every day A. It; do B. That; to do C. This; to do D. It; to do. ( ) 30. --- _____________ ? – I have a sore back. A. What‘s the wrong B. What‘s matter C. What‘s trouble D. What‘s wrong ( ) 31. Mr Green ______for America the day after tomorrow. A. left B. leaves C. is leaving D. is going to leave ( ) 32. I‘m hungry. Would you please give me ______to eat? A. delicious something B. something delicious C. anything delicious D. nothing delicious ( ) 33.Tom goes to school ________every day. A. by a bus B. by his bike C. by buses D. on foot
Teaching Plan 学校：云南师范大学 学院：外国语学院 专业：英语教育 姓名：单坤妍&曹慧仙 学号：114050282&114050281 2013年10月19日星期六
Teaching Plan Name : Shan Kunyan & Cao Huixian No: 114050282& 114050281 Teaching Materials:Go for It (Unit 6 : Do you like bananas ?) ( period: 1 ) Students’ level : Junior 1 1:Teaching content :SectionA(1a-1c) (1)Vocabulary: food, hamburger, tomato, ice-scream, salad, strawberry, pear, milk, bread, ,apple, banana (2)Structure : Yes/No questions and short answers Affirmative and negative statement Examples : Do you like bananas? Yes , I do ./No , I don’t. Do you like salad ? Yes , I do ./No , I don’t. 2:Teaching aim : (1) To learn to use words about some foods . (2) To enable students to ask and answer easy questions about likes and dislikes . 3: Function : Talk about likes and dislikes about foods . 4: Teaching methods : 3P model 5: Teaching aids: pictures , real objects , stick figures 6: Teaching Time: 45 minutes
新课标人教版初中英语七年级下册英语精品试题及答案本试卷满分95分考试时间90分钟 第一卷（选择题共40分） 一．单项选择（每小题1分共 15分） 21.Bob couldn’t buy the dictionary becuase he had___money with him. A.a few B.few C.a little D.little 22.The old teacher is a friend_____. A my brother’s B my brother C of my brother’s D of a brother 23.----Did you see the football match last night? -----Yes,I have never seen____. A such a B so a C such an D so an 24.----Is that red bike Miss Gao’s? -----Yes,it is____. Bautiful,is’t it? A his B our’s C hers Dshe’s 25.If you want to book a round-trip ticket,you will have to pay___200yuan. A more B other C the other D another 26.That’s the only thing_____can’t be forgotten in my life. A that B which C who D \ 27.Since you are______trouble, why not ask_____help. A in,for B in，to C with,for D with,to 28.It’s raining so____that we can____go out. A hard,hard B hardly,hardly C hard,hardly D hardly,hard 29.She prefers_____rather than_____. A write,read B to write,read C to write,to write D write,to read 30.----Do you know_____man on TV? -----Yes,he is_____active person. A the,the B a,an C the,an Da,the 31.Personal computers_____in1976,It has changed the whole world. A invented B are invented C have been invented D were invented 32._____he is only 8 years old,he knows more about science than his father. A but B though C so D because 33.-----Did you arrive late? ------No,I just managed______. A to make B to get it C to make it D to make them 34.His parents were worried that he____too much time chatting on line. A spend B cost C paid D had
七年级英语下期末测试卷 Ⅰ.选择填空（30分） ( )1.He likes interesting things with other people. A.to talk to B.to talk about C.to talk with D.discuss ( )2.Steve down and did the reading an hour ago. A.sit B.sits C.sitting D.sat ( )3.What about a walk after dinner? A.take B.took C.taking D.takes ( )4.We London. https://www.doczj.com/doc/aa15998693.html,es from B.are from C.be from D.was from ( )5.Do you want home now? A.go B.going C.to go D.to go to ( )6.They enjoy football every weekend. A.play B.playing C.to play D.plays ( )7.----What your parents ? ----They are both doctors. A.does, do B.do, do C.are, doing D.job, do ( )8.----Where is Gina? ----She . A.likes football B.often plays soccer C.is a good player D.is playing soccer ( )9.----How’s it ? ---Not bad. A.go B.going C.goes D.went ( )10.----I am going to Beijing for a holiday. ---- . A.Goodbye B.You are right C.It’s good D.Have a good time ( )11.The girl like her mother. She is short and heavy,but her mother is tall and thin. A.isn’t B.aren’t C.don’t D.doesn’t ( )12.Can you give me ?
2019版高考英语一轮复习专题训练第二部分专题十二情态动词 和虚拟语气 1.[2017天津,2]My room is a mess, but I clean it before I go out tonight. I can do it in the morning. 2.[2016北京,31]I love the weekend, because I get up early on Saturdays and Sundays. 3.[2015四川,2]You be careful with the camera. It costs! 4.[2015北京,34]If I (see) it with my own eyes, I wouldn’t have believed it. 5.[2015重庆,7]Without his wartime experiences, Hemingway (write)his famous novel A Farewell to Arms. 6.[2014江西,30]Life is unpredictable; even the poorest become the richest. 7.[2014陕西,23]We would rather our daughter (stay) at home with us, but it is her choice, and she is not a child any longer. 8.[2013天津,9]No one be more generous; he has a heart of gold. 9.[2013新课标全国Ⅱ,6]Since nobody gave him any help, he have done the research on his own. 10.[2013江苏,30]I should not have laughed if I (think) you were serious. 11.[2015四川改错]What do you think I should do? If you are me, would you talk to them? 12.[2014新课标全国Ⅱ改错]We can lie on the grass for a rest, or sat by the lake listening to music. 答案 1.needn’t 句意:我的房间里乱糟糟的,不过我今天晚上出门之前没必要打扫,我可以上午打扫。根据空后的"I can do it in the morning."及句意可知,空处表示"没有必要"。 2.needn’t 句意:我喜欢周末,因为在星期六和星期天我不需要早起。语境表示"不需要,不必",故用needn’t。 3.must 句意:你一定要小心这个相机。它很贵的!根据语境可知,空格处用must"一定"。 4.hadn’t seen 句意:如果不是亲眼所见,我是不会相信的。根据主句谓语"wouldn’t have believed"可知,这里考查的是if条件句中对过去情况的虚拟,if条件句中应用过去完成时,故答案为hadn’t seen。
新目标人教版英语七下 全册教案 Unit 1 Where’s your pen pal from? Language goals: ●In this unit students learn to talk about countries, nationalities and languages. ●Ask and tell where people live. New languages: ●Where’s he / she from? ●He / She is from Australia / England / China / France / Singapore / Australia. ●Where does he / she live? He / She lives in Sydney. ●What language do you speak? I speak English. ●What’s your / his / her favorite subj ect? ●My / His / Her favorite subject is English. ●Does he / she have any brothers and sisters? Yes, he/ she does. / No, he / she doesn’t. Difficult points: 1. Listening for the information about countries, nationalities and languages. Write an e-mail about oneself. Describe the new students in class. 2. Where questions with from Where questions with live What questions Teaching aids: ● A tape recorder Teaching periods: ●Period 1:Section A中1a, 1b, 1c ●Period 2:Section A中2a, 2b, 2c，2d ●Period 3:Section A中3a, 3b, 4
一般过去时 【概念引入】 I. 何时使用一般过去时？ 一般过去时表示在过去某个时间里发生的动作或存在的状态。 例如：Lin Tao left for Shanghai at 8:00 yesterday morning. 林涛昨天早上八点去上海了。 He was ill last night. 昨晚他生病了。 它可以具体分为以下几种情况： 1）表示过去经常或反复发生的动作。 例如：Li Tao always went to work by bus last term. 上学期李涛一直乘公共汽车上班。 2）表示已故的人曾经做过的事情。 例如：Lao She wrote many great works. 老舍写过许多脍炙人口的作品。 3）表示过去所发生的一系列的动作。 例如：The old man came into the room, took off his clothes and went to bed. 这位老人走进屋，脱下衣服，然后上床睡觉了。 Mr. Black got up at six o'clock this morning, dressed, had breakfast, and went to work. 布莱克先生今天早上六点起床、穿衣服、吃饭，然后去上班了。 II.如何识别一般过去时？ 每个时态都会有其独特的标志性词语（主要是时间状语），我们可以称其为“标志词”。一般过去时常见的标志词有： 1. yesterday, the day before yesterday. 2. last week / year / month / term …(简称last系列) 3. two hours ago, three years ago, a moment ago…(简称ago系列) 4. in / on + 过去的年/月/日，如in 1999, on April, 2005 5. just now, once upon a time, one day… 【用法讲解】 Ⅰ. be动词的一般过去时。 在使用一般过去时的句子中，如果句子的谓语是be动词，就要将be动词变为过去式。主语是第一、第三人称单数，be用was；如果是第二人称或者其他人称复数，be用were。它的一般疑问句是把was （were）提到句首；否定句是在was（were）的后面加not。特殊疑问句是在一般疑问句的前面加特殊疑问词。 例如：My mother was busy last night. 我的妈妈昨天晚上很忙。（肯定句） We weren’t at school at that time. 那时我们不在学校。（否定句） Were you at home yesterday? 你昨天在家吗？（一般疑问句） Where were you last night? 你昨天晚上在哪里？（特殊疑问句） 注意：there be句型中be动词的使用。 当主语是单数名词或者不可数名词时be动词用单数；当主语是名词复数时be动词用复数。 例如：There was a strong wind just now. 刚才有一阵强风。 There were many people in the supermarket last night. 昨天晚上超市有很多人。 Ⅱ. 行为动词的一般过去时。 1）基本用法。 谓语动词是行为动词的句子，在一般过去时中，要将作谓语的行为动词变成过去式。行为动词的
情态动词的全称是情态助动词，助动词则分为两种：基本助动词和情态助动词。 为什么要细分一下呢？因为它们是有区别的： 基本助动词有三个：be, have, do 情态动词有大约14个：may, might; can, could; will, would; shall, should;must, need, dare, used to, ought to. had better 构成时态或语态的助动词，提前或否定时出现的动词。 换句话说就是：助动词是当形式需要它的时候才出现，不该它出现就哪儿凉快哪儿呆着。 比如由于时态或语态的要求，比如疑问句或否定句的要求等等，需要它的时候才出现，不需要的时候并没它们什么事。 它们的区别： 1、每个情态动词都有基本意义，基本助动词则没有，只具有语法作用。 2、情态动词后面接原形动词，也就是秃头不定式；助动词要看时态或语态等等情况变化。 3、情态动词没有人称和数的变化，而助动词则有。 4、只有现在和过去两种形式，但可以表示过去、现在和将来时间。
5、情态动词没有非谓语动词形式，而助动词有。 巩固练习： 1、____ you understand the different kinds of English these people are using? A. Will B. Can C. May 2、You ____ be Carol. You haven’t changed a bit after all these years. A. must B. might C. should 3、— I think I’ll give Bob a ring. — You ____. You haven’t been in touch with him for ages. A. will B. may C. should 4、Although you ____ find bargains in London, it’s not generally acheap place to shop. A. should B. need C. can 5、It is usually warm in my hometown in March, but it ____ be rather cold sometimes. A. might B. can C. must 6、If you ____ go, at least wait until the storm is over. A. should B. must C. may 7、— What are you going to do this Saturday?
新目标七年级暑期第一次测试 基础知识运用 六．选择填空（共20小题，每小题1分，计20分） A.选出划线部分意思相同或相近，并能替换划线部分的选项。（共4小题，每小题1分，计4分） 31.Sorry, we are short of fish. （）32.What else did he say? （）33.we have no idea about the music festival. （）34.My parents aren’t at home. B.以下各题的A,B,C三个选中选出正确答案。 （）35.The girl with __________ umbrella is wearing __________ uniform of this middle school. A.an ; an B.a;an C.an;a （）36.---What did you do __________last weekend. ---I washed my father’s car __________ Sunday afternoon. A.on;on B./;on C.for;/ （）37.Things in the museum are __________ so I’m not __________ them. A.b boring;interested in B.excellent;getting popular C.interesting;interested in （）38.the dog was __________ when it cross the road. A.dangerous B.danger C.in danger （）39.---Could you tell him to call me back? --- __________ A.Sure,no problem B.No,I couldn’t. C.It’s my pleasure. （）40.---Mom remember to wake me up at 6 a.m. I have an important meeting. --- __________ A.Yes, pleasure. B.It’s hard to say. C.OK,I will. （）41.It’s raining heavily. __________go to the restaurant, Sandy. A.Why not B.Why don’t C.Would you like （）42.She worked __________ a waitress and every day, she needs 20 minutes to go to work__________. A.to; in bus B.like;take the bus C.as;by bus （）43.He __________ his home 5 years ago and he always __________ his family. A.leave;misses B.forgot;missed C.left;misses （）44.You must tell your parents __________. A.who you went with B.who did you go with C.who with you go （）45. __________number of the tall buildings in my hometown ________growing. A.The;is B.The;are C.A;is （）46.I’m new __________, I don’t know the way __________. A.in a town;on the station B.in town;to the station C.in a town;between the station C. 补全对话。（共4小题，每题1分，计4分） Tim:Hey,Ken! Summer holiday is coming! Ken:Yeah! __________ Tim:Well,I am going to Taiwan with my classmates.
七年级（下）期末试卷 英语 一、选择填空（共15小题；每小题1分，满分15分）从每小题所给的A、B、C三个选项中，选出可以填入空白处的正确答案． 14．（1分）Our classroom building has floors．Our class is on the floor．（）A．three；third B．three；three C．third；third 15．（1分）My sister songs very well．She an English song at my birthday party yesterday evening．（） A．sings；is singing B．sings；sang C．sang；sang 16．（1分）﹣Look at the sign，"No Parking"． ﹣Oh，sorry．I see it．（） A．don't B．didn't C．can't 17．（1分）My father is always ．He has no time to help with my homework．（）A．kind B．smart C．busy 18．（1分）﹣Do you want me to help you，Tom？ ﹣No，thanks．I can make it ．（） A．myself B．himself C．yourself 19．（1分）You'd better on the bus．It's bad for your eyes．（）A．read B．to read C．not read 20．（1分）your warm clothes．It's very cold today．（） A．Put up B．Put on C．Put away 21．（1分）﹣How do you usually go to work？ ﹣I usually go to work because it's easy to park．（） A．by plane B．by bike C．by subway 22．（1分）﹣do you go to the library？ ﹣Once a week．（） A．How often B．How many C．How long 23．（1分）﹣May I use your eraser？
.初中英语人教版新目标英语七年级（下） Unit 3 How do you get to school?sectionA(2a-2e) 课例分析 一。对教学内容的反思 （一）．教材分析：本课位于七年级英语下册第单三元的第二节。 1.主要通过学习出行方式 2.掌握重点句型 1.how far is it from…to…? It’s… 2.how long does it take …to…?it takes sb some time to do （二）学情分析： 1.出行方式比较贴近生活。 2. how far,how long 开头的句子及答语学生应用比较难，学习相对困难。 （三）教学目标：根据教材内容和学生情况确定以下几方面的教学目标。 1. 知识与技能 掌握本课的词汇和重点句型并学会应用 2.过程与方法 提高学生的听，说，读，写及培养学生运用所学知识，解决实际问题的能力。 3.情感态度与价值观能力。 使学生在人际交往中学会尊重，学会沟通，更学会交换不同的看法以增进情谊。 （四）教学重点：1本课词汇。 2. 运用主要语言结构：1.how far is it from…to…? It’s… 2.how long does it take …to…?it takes sb some time to do （五）教学难点：运用主要语言结构： 1.how far is it from…to…? It’s… 2.how long does it take …to…?it takes sb some time to do 二、对教学过程的反思在教授这一课时，我积极倡导自主、合作、探究的学习方式，充分激发学生的主动意识和进取精神，以小组合作探究为主，学生为主体，教师为主导，以交流型课堂为特征，以激发学生的学习兴趣为为核心，以“让学生动起来，课堂活起来，效果好起来”为宗旨，对本堂课的教学进行了如下设计： 根据本课的学习内容分为自主学习，合作探究; 交流展示，精讲点拨；听力训练，能力提升；知识总结，系列训练当堂达标；教学反思。几个部分组成 （一）、情景导入、明确目标 【预习指导】自我预习： 一、扫清障碍 根据音标读出2a---2e的单词。 二、课本预习： 熟读2a 并完成填空，复习数词 熟读并翻译2e和grammar focus 组织2d对话。 三，预习效果检查。 1,写出基数词1----21 2，写出20------100(整十） 3,写出并读出下列单词或短语 分钟千米，公里每天新的，刚出现 骑自行车多远多久一百祝你玩得愉快 我不很肯定
考点19 情态动词 高考频度：★★★★★ 【命题解读】 高考研究英语中常用的情态动词主要有can，could，may，might，must，will，would，shall，should，ought to，dare，need，used to，had better等。在学习情态动词时应注意以下几点：同一情态动词表示不同的意义的情况；情态动词后跟各种形式的用法；尤其要注意＂情态动词+完成式＂是高考中的重点所在。 【命题预测】 情态动词是各地高考试题中的必考项目，每年高考单独命题区的单项填空必有一道考查情态动词的项目。新课标卷主要在语法填空和短文改错中考查。考点依次是：推测(可能性)→请求/允许→必要性→特殊用法。试题的立意不偏不怪，但有效信息越来越隐蔽，语境越来越真实，考查角度越来越细致，这些因素在很大程度上增加了试题的难度。 【复习建议】 1. 真实的语境中对情态动词的理解和把握； 2. 掌握情态动词表示推测和可能性的用法； 3. 掌握情态动词表达＂情感、态度、语气等＂方面的用法。 考向一can，could与be able to的用法 1．表示能力，意为＂能，会＂。 ?Many people can use the computer. 许多人会用电脑。 ?If you have a good sleep，you will be able to work out this problem. 如果你好好睡一觉，你将能够解出这道题。 ?I could have worked out the problem，but I was too nervous. 我本来可以解决这个问题，但我太紧张了。 2．can/could表示惊讶，常用在否定句和疑问句中。 ?How can you treat me like that? 你怎么能那样对我？
Starter Unit 1 Good morning! 授课班级授课日期 授课类型Starter Unit 1新授课学时数 The First Period ( 1a—1c) 教学目标 1. Knowledge and abilities Let students know the eight English names and remember them. Let students know how to greet people in the morning. 2. Process and methods Through listening and reading, let students grasp the simple greetings. 3. Emotion, attitude and values Motivate students’interests of learning English. 教学内容 学习八个人名。Alice, Bob, Cindy, Dale, Eric, Frank, Grace, Helen 学习打招呼的用语： Hello!/ Good morning! 重点难点 八个人名Alice, Bob, Cindy, Dale, Eric, Frank, Grace, Helen 句型：Hello! Good morning! 教学方法任务型教学、直观教学法、模仿示范法、情景教学和合作学习法 教学用具图片、黑板、录音机 教学过程设计备注 教学步骤 Step1. Warming-up 1.T wears a name card with an English name on it, then points to the name card and have an introduction. 2. Greet the whole class and help them to say, Hello, … Good morning, 师生初次见面，教师通过自我介绍和问候学生，让学生放轻松，消除与教师间的陌生感，开始亲近教师。 Step2. Play a game. T gets ready for a list of English names for boys and girls. Play the game like this: T says a letter, for example C, then let the Ss tell the letters which is before and after C. The one who says B, D first is the winner. The winner can get a chance to choose an English name first or he can give the chance to his friend. 绝大多数学生都会背诵26个字母表，因此学生参与这个游戏会相当积极。通过这个游戏首先可以锻炼他们迅速反应的能力；以英语名字作为奖励，也使学生较有新鲜感，让他们自己选择自己的名字，使他们会更容易记住自己的名字。Step3. Presentation. Show a picture of a girl and give the name under the picture, teach Alice. In the same way teach the other seven names. 图画和名字结合起来，加强学生的感性认识，有助于记忆。并为后面的游戏做好
My daughter I have a good daughter. She is a lovely girl. Her Chinese name is Wu Yu and her English name is Angelia. Now she is eight years old. Her birthday is on April 17th. She lives in Chengdu. She likes pink and white best. She has a good eating habit. She eats healthy food every day. For breakfast, she has an egg, some milk , two pieces of bread and some fruit. She has lunch at school, she likes chicken and some vegetables. For dinner, she likes some vegetables like carrots, tomatoes and broccoli(西兰花），but she doesn't like eating meat because she doesn't want to be fat. She has lots of hobbies. She likes doing sports. Ping-pong is her favorite sport. She often plays it with her father on weekends. She loves drawing, dancing and reading. And she is good at telling stories (讲故事). She wants to be a dance instructor (舞蹈老师）one day. From Monday to Friday, she has classes at school. Her first class begins at 8:00 and her last class finishes at 4:30. She thinks math is difficult but useful. And her math teacher is very kind and often helps her with math. So math is her favorite subject. At school, she has lots of good friends. She often plays with them after class. This is my daughter. Do you want to make friends with her? Task One 根据内容填写表格
专题限时检测(八) 情态动词和虚拟语气 (共3组，限时20分钟) [模拟题组一] 1．(2019·无锡高三一模)According to the school rule, no child ________ be allowed out of the school, unless accompanied by his own parents. A．should B．must C．shall D．can 解析：选C 句意：根据校规，孩子不可以离开学校，除非有他自己的父母的陪伴。shall 用于第三人称，在条约、规定、法令等文件中表示义务或规定，意为“应该，必须”。 2．(2019·无锡一模)—I can't understand why he ________ so angry.I meant no offence. —It's typical of him to be so sensitive. A．must have been B．should have been C．might have been D．can have been 解析：选B 句意：“我不理解为什么他竟然会如此生气。我无意冒犯。”“他一向是个很敏感的人。”should此处意思为“竟然”。 3．(2019·苏、锡、常、镇二模)—Sherry rang to say she was too busy to come. —Well, she ________ say that. She is always making excuses. A．mustn't B．would C．needn't D．should 解析：选B 句意：“雪莉打电话说她太忙了不能来。”“好吧，她老是那样说。她总是给自己找借口。”根据答语中的“She is always making excuses”可知，此处应用would，表示过去习惯性的动作。 4．(2019·常州一模)Using AI, many companies are now conducting experiments that ________ possible just a few years ago. A．would have been B．might have been C．shouldn't have been D．couldn't have been 解析：选D 句意：如今使用人工智能后，许多公司都可以做在几年前不可能做的实验。句意为否定，表示过去的可能性，故用could not have been。 5．(2019·徐州、淮安、连云港一模)—It's really great to have a computer to store my photos. —Don't count on it too much.It ________ break down and you'd better make a copy