考研英語(yǔ)詞匯練習(xí)題(共38頁(yè))

1、精選優(yōu)質(zhì)文檔-傾情為你奉上考研英語(yǔ)一級(jí)詞匯練習(xí)題1. I shall have companion in the house after all these _ years.A) single B) sole C) alone D) lonely2. The newest satellite can _ a thousand telephone conversations and a colour TVprogram at the same time.A) carry B) extend C) bring D) take3. The bridge was named _ the hero wh

2、o gave his life for the cause of the people.A) after B) with C) by D) from4. If these shoes are too big, ask the clerk to bring you a smaller _.A) suit B) pair C) one D) set5. I am sorry I _ your glasses off the desk when I was wiping it.A) drew B) hit C) struck D) knocked6. It is not difficult to _

3、 the idea that machines may communicate information to us.A) admit B) receive C) accept D) convince7. As the shortage of certain metals approaches, others must be found to take their _.A) share B) place C) role D) shape8. Although the weather was very had, the buses still ran on _.A) list B) plan C)

4、 schedule D) arrangement9. Language can be defined as a tool by which human beings _ with one another.A) associate B) connectC) correspond D) communicate10. If you do not fasten your safety belt, your chances of being _ will be greater.A) beaten B) hurt C) damaged D) stricken11. I found my daughter

5、sitting in the kitchen, crying _.A) strongly B) bitterly C) heavily D) deeply12. What _ to him is whether the job allows him to pursue his studies.A) matters B) refers C) happens D) applies13. Cambridge has announced plans to establish a business school _ the masters degreein business administration

6、.A) representing B) presenting C) offering D) supplying14. It is _ impossible to find a good educational computer program in this part of thecountry.A) barely B) hardly C) merely D) nearly15. What he told us about the affair simply doesnt make any _.A) sense B) idea C) meaning D) significance16. Hit

7、ler set out to conquer all of Europe in the belief that the Germans were the master_.A) race B) human C) blood D) brains17. Franklins ability to learn from observations and experience _ greatly to his successin public life.A) contributed B) owed C) attached D) related18. I cannot give you _ for the

8、type of car you sell because there is no demand for it inthe market.A) an expense B) a charge C) a purchase D) an order19. In the experiment we kept a watchful eye _ the developments and recorded everydetail.A) in B) at C) for D) on20. Before he left for his vacation he went to the bank to _ some mo

9、ney.A) pull B) draw C) gain D) pick21. Though the long-term _ cannot be predicted, the project has been approved by thecommittee.A) effect B) effort C) affect D) afford22. I used to smoke _ but I gave it up three years ago.A) seriously B) heavily C) badly D) severely23. He decided to make further im

10、provements on the computers design _ the light ofthe requirements of customers.A) on B) for C) in D) with24. In preparing scientific reports of laboratory experiments, a student should _ hisfindings in logical order and clear language.A) furnish B) propose C) raise D) present25. I am _ of your stupi

11、d conversation.A) annoyed B) worried C) tired D) angry考研英語(yǔ)一級(jí)詞匯練習(xí)題答案1-5 DAABD6-10 CBCDB11-15 BACDA16-20 AADDB21-25 ABCDC1動(dòng)詞時(shí)態(tài)練習(xí)題1. By the time you arrive in London, we _ in Europe for two weeks.A shall stay B have stayedC will have stayed D have been staying2. Mr. Smith _ a novel for the last 10 mont

12、hs, but he hasnt finished it yet.A has written B is writingC has been writing D had been writing3. By the year 2010, scientists probably _ a cure for cancer.A will be discovering B are discoveringC will have discovered D have discovered4. I _ to visit them yesterday, but someone came to see me just

13、when I was about to leave.A planned B had plannedC would plan D was planning5. Greater efforts to increase agricultural production must be made if food shortage _ avoided.A is to be B can beC will be D has been6. Someone _ my book. I _for it for the last ten minutes, but I cant see it anywhere.A too

14、k; have been looking B has taken; am lookingC took; was looking D has taken; have been looking7. Carey didnt go to the party last night because she _ the baby for her sister until 9:30.A must have looked after B would have to look afterC had to look after D should have looked after8. The school boar

15、d listened quietly as John read the demands that his followers _ for.A be demonstrating B demonstrateC had been demonstrating D have demonstrated9. She felt suitably humble just as she _ when he had first taken a good look at her hair wavedand golden, nails red and pointed.A had B had hadC would hav

16、e had D has had10. Ever since Picassos paintings went on exhibit, there _ large crowds at the museum everyday.A have been B has beenC is D are being11. Until then, his family _ from him for six months.A didnt hear B hasnt heardC hasnt been hearing D hadnt heardl2. The crazy fans _ patiently for two

17、hours，and they would wait till the movie star arrived.A were waiting B had been waitingC had waited D would wait13. Turn on the television or open a magazine and you _ advertisements showing happy,balanced families.A are often seeing B will often seeC often see D have often seen214. The article sugg

18、ests that when a person _ under unusual stress he should be especiallycareful to have a well-balanced diet.A is B wereC be D was15. After driving for thirty miles, she suddenly realized that she _ in the wrong direction.A had been driving B has been drivingC drove D had driven16. That was the first

19、time the old lady _ her suffering to others.A was telling B had toldC have told D told17. I would have gone to visit him in the hospital had it been at all possible, but I _ fullyoccupied the whole of last week.A were B had beenC have been D wasl8. Before the first non-stop flight made in 1949, it _

20、 necessary for all planes to land forrefueling.A would be B has beenC had been D would have been19. It seems oil _ from this pipe for some time. Well have to take the machine apart to put itright.A had leaked B has been leakingC leaked D is leaking20. While people may refer to television for up-to-t

21、he-minute news, it is unlikely that television_ the newspaper completely.A will replace B replaceC have replaced D replaced被動(dòng)語(yǔ)態(tài)練習(xí)題1. I appreciated _ the opportunity to study abroad two years ago.A having been given B having givenC having given D to have been given2. Between 1897 and 1919 at least 29

22、 motion pictures in which artificial beings were portrayed_.A had produced B have been producedC would have produced D had been produced3. Our modem civilization must not be thought of as _ in a short period of time.A being created B to have been createdC having been created D to be created4. In tha

23、t country, guests tend to feel they are not highly _ if the invitation to a dinner party isextended only three or four days before the party date.A admired B regardedC expected D worshipped5. I cut my finger two days ago and it became badly _.A infected B affected C effected D diseased36. It is anno

24、unced that a wallet has been found and can be _ at the managers office.A declared B obtained C reclaimed D recognized7. Up to 19 witnesses were _ to have received payments for telling their stories to newspapers.A stated B remarked C said D told8. Teenagers need the confidence that comes from achiev

25、ing success and knowing that theiraccomplishments are _ by others.A claimed B admired C ignored D surpassed9. The fifth generation computers, with artificial intelligence, _ and perfected now.A developed B have developedC are being developed D will have been developed10. He returned at midnight and

26、found his house _.A had broken into B was broken intoC to be broken into D had been broken into11. After such a long journey, my shoes want _.A to mend B mended C to be mending D mending12. _ to have escaped via Heathrow Airport.A They say the robbers B They are said the robbersC The robbers say D T

27、he robbers are said13. Once environmental damage _, it takes many years for the system to recover.A has done B is to do C does D is done14. Mr. Johnson preferred _heavier work to do.A to be given B to have given C to be giving D having given15. The last half of the nineteenth century _the steady imp

28、rovement in the means of travel.A has witnessed B witnessed C was witnessed D is witnessed情態(tài)動(dòng)詞練習(xí)題1. It is cold in the room. They _ have turned off the steam.A must B ought to C should D out2. Mary _ my letter; otherwise she would have replied before now.A has received B ought to have receivedC could

29、nt have received D shouldnt have received3. My pain _ apparent the moment I walked into the room, for the first man I met askedsympathetically: “Are you feeling all right?”A must be B had C must have been D had to4. As it turned out to be a small house party, we _ so formally.A neednt dress up B did

30、 not need have dressed upC did not need dress up D neednt have dressed up5. When the country calls you for help, you cannot but_.A have gone B going C go D to go6. This is an opportunity that comes once in a lifetime. We _ it pass.A dont have to let B may not letC mustnt let D couldnt let7. How I re

31、gretted the hours wasted in the woods and fields, the days when I had played and_.A had studied B may have studied4C must have studied D should have studied8. Some actresses like to be surrounded by a crowd of people all the time, while others _ ontheir own instead.A have got to be B had better beC

32、would rather be D might as well be9. She _ drive her car to work, but now she rides a bicycle for the sake of health.A used to B is used to C use to D was used10. Carey didnt go to the party last night because she _ the baby for her sister until 9:30.A must have looked after B would have to look aft

33、erC had to look after D should have looked after11. From the tears in Nedras eyes we can deduce that something sad_.A must have occurred B would have occurredC might be occurring D should occur12. According to one belief, if truth is to be known it will make itself apparent, so one _ waitinstead of

34、searching for it.A would rather B had toC cannot but D had best代詞練習(xí)題1. No bread eaten by man is so sweet as _ earned by his own labor.A one B that C such D what2. Can you break a five-pound note? I havent _ with meA nothing small B anything smallerC something smaller D something small3. I have been

35、to the doctors about my headache. He says there is_, but I must lie up for a fewdays.A something serious B anything seriousC not serious D nothing serious4. There was no meeting of minds because neither could get the wavelength of_.A other B the otherC either D others5. Inaccurate or indefinite word

36、s may make _difficult for the listener to understand themessage which is being transmitted to him.A that B itC so D this6. The number of registered participants in this years marathon was half_.A of last years B those of last yearsC of those of last year D that of last years7. There are thirteen or

37、more of vitamins, and if _is missing a deficiency disease becomesapparent.A any B some C anything D something8. A theater with poor sight lines, poor sound-shaping qualities, and too few entries and exits willnot work for _purpose.A their B its C those D that59. William the Conqueror built the Tower

38、 of London to protect himself from _he hadconquered.A each other B them C it D those10. When it has accomplished its mission, it can be ready for _trip in about two weeks.A new B another C certain D subsequent11. These refrigerators are equal in price to, if not more expensive than, _at the other st

39、ore.A anyone B the others C that D the ones12. A good writer is _who can express the commonplace in an uncommon way.A that B he C one D thisl3. In fact _of the contradictory judgments is valid.A some B each C every D bothl4. _Germans like to drink beer.A The most B Most C Most of D Most of the15. As

40、 I was just getting familiar with this job, I had _to ask my boss.A many B most C more D much16. It is one thing to enjoy listening to good music, but it is quite _to perform skillfullyyourself.A other B another C some D any17. He is _of an actor.A anybody B anyone C somebody D something18. The indi

41、vidual TV viewer invariably senses that he or she is _an anonymous, statisticallyinsignificant part of a huge and diverse audience.A everything except B anything butC no less than D nothing more than19. A variety of activities should be organized so that participants can remain active as long asthey

42、 want and then go on to _else without feeling guilty and without letting the otherparticipants down.A everything B anything C nothing D something動(dòng)詞時(shí)態(tài)題目解析1. 正確答案為C 項(xiàng)。根據(jù)從句的提示可知，主句表示到將來(lái)某個(gè)時(shí)間點(diǎn)為止已經(jīng)發(fā)生的動(dòng)作，所以使用將來(lái)完成時(shí)。如果D 項(xiàng)改為will have been staying，則也是正確的。句子譯文：“等你到達(dá)倫敦的時(shí)候，我們?cè)跉W洲已經(jīng)呆了兩周了?！?. 正確答案為C 項(xiàng)。根據(jù)語(yǔ)境提示可知，史密斯先生

43、寫小說(shuō)從過(guò)去一直持續(xù)至今，所以使用現(xiàn)在完成進(jìn)行時(shí)。句子譯文：“史密斯先生在過(guò)去10 個(gè)月一直在寫一本小說(shuō)，但是還沒有完成?！?. 正確答案為C 項(xiàng)。根據(jù)by the year 2010 這一時(shí)間提示，可知句子應(yīng)使用將來(lái)完成時(shí)。句子譯文：“到了2010 年，科學(xué)家或許已經(jīng)找到癌癥的治療方法?！?. 正確答案為B 項(xiàng)。盡管句子中有表示一般過(guò)去時(shí)的時(shí)間提示詞yesterday，但是在本題中卻成了干擾信息。根據(jù)轉(zhuǎn)折連詞but 之后的信息，說(shuō)明plan 這個(gè)動(dòng)作是發(fā)生在someone cameto see me 之前，應(yīng)表示“過(guò)去的過(guò)去”，故此應(yīng)使用過(guò)去完成時(shí)。句子譯文：“昨天我本打算去看他們，但當(dāng)我正

44、要走的時(shí)候有人來(lái)看我了?！?. 正確答案為A 項(xiàng)。在條件狀語(yǔ)從句中，不能使用will 表示將來(lái)時(shí)，但可以使用be to 結(jié)構(gòu)，表示按計(jì)劃、要求等要做的事。句子譯文：“如果要避免糧食短缺，就必須加大努力提高農(nóng)業(yè)產(chǎn)量。”6. 正確答案為D 項(xiàng)。前一句話所表達(dá)的事情對(duì)后一句話的情況造成了影響，所以使用現(xiàn)在完成時(shí)。在后一句話中，不難看出，look 這一動(dòng)作從十分鐘前開始，持續(xù)到現(xiàn)在，所以應(yīng)使用現(xiàn)在完成進(jìn)行時(shí)。句子譯文：“有人拿走了我的書。前十分鐘我一直在找，可哪兒也找不到?！?. 正確答案為C 項(xiàng)。本句表達(dá)昨晚進(jìn)行的動(dòng)作，所以用一般過(guò)去時(shí)。句子譯文：“昨晚凱里沒有去參加聚會(huì)，因?yàn)樗仨毺娼憬阏湛春⒆拥?/p>

45、九點(diǎn)半?！?. 正確答案為C 項(xiàng)。本題考查過(guò)去完成進(jìn)行時(shí)，表達(dá)動(dòng)作從過(guò)去的過(guò)去開始，一直持續(xù)到過(guò)去。句子譯文：“約翰朗讀他的追隨者們示威游行希望獲得的要求，學(xué)校董事會(huì)靜靜地聽肴?！?. 正確答案為A 項(xiàng)。本題考查動(dòng)詞的過(guò)去完成時(shí)。結(jié)合上文可以看出，空格處的had 其實(shí)是had felt humble 的省略表達(dá)。句子譯文：“她感到適宜的謙恭，就像他當(dāng)初第一次仔細(xì)看到她的時(shí)候一樣，那時(shí)，她一頭金黃的卷發(fā)，指甲又尖又紅?！?0. 正確答案為A 項(xiàng)。從句由時(shí)間連詞since 引導(dǎo)，時(shí)態(tài)是一般過(guò)去時(shí)，主句應(yīng)使用現(xiàn)在完成時(shí)。句子譯文：“自從畢加索的油畫展出以來(lái)，每天都有大批觀眾來(lái)博物館參觀。”11. 正

46、確答案為D 項(xiàng)。由時(shí)間提示詞until then 可知，句子所表達(dá)的是過(guò)去之前的情況，所以應(yīng)使用過(guò)去完成時(shí)。句子譯文：“到那時(shí)為止，他的家人已經(jīng)半年沒有聽到他的消息了?！?2. 正確答案為B 項(xiàng)。本題考查過(guò)去完成進(jìn)行時(shí)。句子譯文：“瘋狂的影迷耐心地等了兩小時(shí)，他們要一直等到這個(gè)影星到來(lái)為止?！?3. 正確答案為B 項(xiàng)。前一個(gè)分句的形式為祈使句，表示條件，由and 引出結(jié)果，表示結(jié)果的分句使用一般將來(lái)時(shí)。句子譯文：“如果打開電視或者雜志，你會(huì)經(jīng)?？吹奖憩F(xiàn)幸福和諧家庭的廣告?！?4. 正確答案為A 項(xiàng)。本題考查一般現(xiàn)在時(shí)。需要注意的是，時(shí)間狀語(yǔ)從句并不是suggest的直接對(duì)象，所以動(dòng)詞不使用虛擬

47、語(yǔ)氣。句子譯文：“這篇文章建議，當(dāng)一個(gè)人處于超常壓力下的時(shí)候，應(yīng)該特別注意飲食平衡?！?5. 正確答案為A 項(xiàng)。本題考查過(guò)去完成進(jìn)行時(shí)。句子譯文：“開了30 英里后，她突然意識(shí)到自己一直在朝錯(cuò)誤的方向開車?！?6. 正確答案為B 項(xiàng)。That was the first time 后面的從句應(yīng)使用過(guò)去完成時(shí)。句子譯文：“這是第一次老太太把自己的苦難講給別人聽?！?7. 正確答案為D 項(xiàng)。but 之前的分句是針對(duì)過(guò)去的虛擬表達(dá)，but 之后的分句表達(dá)過(guò)去的真實(shí)情況，應(yīng)使用一般過(guò)去時(shí)。句子譯文：“要是有可能的話，我就去醫(yī)院看他了，可是上周我一直非常忙?！?8. 正確答案為C 項(xiàng)。由時(shí)間提示詞語(yǔ)be

48、fore the first non-stop flight made in 1949 可知，主句表示過(guò)去之前的情況，應(yīng)使用過(guò)去完成時(shí)。句子譯文：“在1949 年第一次直達(dá)飛行之前，所有的飛機(jī)都必須中途著陸以便加油。”19. 正確答案為B 項(xiàng)。本題考查現(xiàn)在完成進(jìn)行時(shí)。句子譯文：“似乎這條管子已經(jīng)漏了一段時(shí)間的油了。我們必須拆開機(jī)器，把它修好?！?0. 確答案為A 項(xiàng)。It is unlikely 表達(dá)將來(lái)的情況，所以從句應(yīng)使用一般將來(lái)時(shí)。句子譯文：“雖然人們可以通過(guò)電視了解最新的消息，但是電視完全取代報(bào)紙的可能性不大?！北粍?dòng)語(yǔ)態(tài)題目解析1. 正確答案為A 項(xiàng)。動(dòng)詞appreciate 要求作賓

49、語(yǔ)的動(dòng)詞使用動(dòng)名詞形式，句子主語(yǔ)和動(dòng)詞give 之間是被動(dòng)關(guān)系，且表示已經(jīng)完成，所以應(yīng)選擇having been given。句子譯文：“我感謝兩年前有機(jī)會(huì)到國(guó)外學(xué)習(xí)。”2. 正確答案為D 項(xiàng)。本題考查被動(dòng)語(yǔ)態(tài)的過(guò)去完成時(shí)。句子譯文：“在1897 至1919 年期間，至少生產(chǎn)了29 部描寫人造生物的電影。”3. 正確答案為C 項(xiàng)。as 是介詞，所以要求作賓語(yǔ)的動(dòng)詞使用動(dòng)名詞形式，動(dòng)詞create 和句子主語(yǔ)之間是被動(dòng)關(guān)系，且表示已經(jīng)完成，所以選擇having been created。句子譯文：“我們的現(xiàn)代文明一定不能被看作是短期內(nèi)創(chuàng)造出來(lái)的?！?. 正確答案為B 項(xiàng)。四個(gè)選項(xiàng)是不同動(dòng)詞的被動(dòng)

50、語(yǔ)態(tài)。admired 表示“受到羨慕，受到欽佩”；regarded 表示“受到尊重，被看重”；expected 表示“被期望”；worshipped 表示“被崇拜”。句子譯文：“在這個(gè)國(guó)家，如果參加宴會(huì)的邀請(qǐng)函在舉行宴會(huì)之前三四天發(fā)出，客人往往會(huì)感覺他們沒有受到高度重視。”5. 正確答案為A 項(xiàng)。前三個(gè)選項(xiàng)是不同動(dòng)詞的被動(dòng)語(yǔ)態(tài)。infected 表示“被傳染，受到感染”；affected 表示“受到影響”；effected 表示“被實(shí)現(xiàn)”；diseased 是形容詞，表示“有病的”。句子譯文：“兩天前，我割破了手指，出現(xiàn)了嚴(yán)重的感染。”6. 正確答案為C 項(xiàng)。四個(gè)選項(xiàng)是不同動(dòng)詞的被動(dòng)語(yǔ)態(tài)。de

51、clared 表示“被宣布，被宣稱”；obtained 表示“被獲得”；reclaimed 表示“被認(rèn)領(lǐng)”，同claimed；recognized 表示“被認(rèn)出”。句子譯文：“據(jù)宣布，有人發(fā)現(xiàn)了一個(gè)錢包，可以到經(jīng)理辦公室認(rèn)領(lǐng)?！?. 正確答案為C 項(xiàng)。stated 表示“被說(shuō)明，被陳述”，remarked 表示“被評(píng)論”，said 表示“據(jù)說(shuō)”，told 表示“被告知”。句子譯文：“據(jù)說(shuō)，有多達(dá)19 個(gè)證人因?yàn)橄驁?bào)社講述他們的故事而接受過(guò)報(bào)酬?！?. 正確答案為B 項(xiàng)。四個(gè)選項(xiàng)是不同動(dòng)詞的被動(dòng)語(yǔ)態(tài)。claimed 表示“被認(rèn)領(lǐng)”；admired 表示“受到羨慕，受到欽佩”；ignored 表示

52、“被忽視”；surpassed 表示“被超過(guò)”。句子譯文：“青少年需要信心，這種信心來(lái)自取得成功以及知道自己的成績(jī)受到別人的欣賞?！?. 正確答案為C 項(xiàng)。本題考查被動(dòng)語(yǔ)態(tài)的現(xiàn)在進(jìn)行時(shí)。句子譯文：“第五代計(jì)算機(jī)具有人工智能，現(xiàn)在正在被開發(fā)和改進(jìn)?！?0. 正確答案為D 項(xiàng)。本題考查被動(dòng)語(yǔ)態(tài)的過(guò)去完成時(shí)。句子譯文：“他回到家，發(fā)現(xiàn)他的家已經(jīng)有人闖入?！?1. 正確答案為D 項(xiàng)。當(dāng)動(dòng)詞want 表示“需要”時(shí)，其用法是sth. wants doing. 或sth. wantsto be done. 句子譯文：“在走了這么長(zhǎng)的路程之后，我的鞋需要修理?！?2. 正確答案為D 項(xiàng)。本題考查sb. is

53、 said to have done sth. 句型，表示“據(jù)說(shuō)，某人做過(guò)某事”。句子譯文：“據(jù)說(shuō)，搶劫犯?jìng)兘?jīng)由希思羅機(jī)場(chǎng)逃跑了?！?3. 正確答案為D 項(xiàng)。主語(yǔ)damage 是動(dòng)詞do 的對(duì)象，所以應(yīng)使用被動(dòng)語(yǔ)態(tài)。其主動(dòng)表達(dá)為do damage，表示“造成破壞”。句子譯文：“一旦環(huán)境遭到破壞，系統(tǒng)需要很多年才能恢復(fù)?！?4. 正確答案為A 項(xiàng)。動(dòng)詞give 和主語(yǔ)之間是被動(dòng)關(guān)系，選項(xiàng)中只有A 項(xiàng)是被動(dòng)表達(dá)。句子譯文：“約翰遜先生更喜歡被分配干較重的活兒?！?5. 正確答案為B 項(xiàng)。動(dòng)詞witness 表示“見證”，和主語(yǔ)是主動(dòng)關(guān)系，并且表達(dá)過(guò)去的情況，應(yīng)該使用過(guò)去時(shí)。句子譯文：“在19 世紀(jì)

54、后半葉，交通工具不斷得到改進(jìn)?！鼻閼B(tài)動(dòng)詞題目解析1. 正確答案為A 項(xiàng)。本題考查“must+現(xiàn)在完成時(shí)”，表示“一定做過(guò)某事”。句子譯文：“房間里很冷。他們一定關(guān)掉了暖氣?！?. 正確答案為C 項(xiàng)。本題考查“couldnt+現(xiàn)在完成時(shí)”，表示“不可能做過(guò)某事”。句子譯文：“瑪麗不可能收到我的信，否則的話，等不到現(xiàn)在她就回信了。”3. 正確答案為C 項(xiàng)。本題考查“must+現(xiàn)在完成時(shí)”。句子譯文：“當(dāng)我走進(jìn)房間的時(shí)候，我的疼痛一定很明顯，因?yàn)槲乙姷降牡谝粋€(gè)人同情地問(wèn)我：你感覺好嗎?”4. 正確答案為D 項(xiàng)。本題考查“neednt+現(xiàn)在完成時(shí)”，表示“本不必做某事”。句子譯文：“這是個(gè)小型家庭聚會(huì)，所以我們?cè)緵]有必要穿戴得這樣正式?！?. 正確答案為C 項(xiàng)。本題考查cannot but 的用法，其后跟動(dòng)詞原形。句子譯文：“當(dāng)國(guó)家召喚你效力的時(shí)候，你不能不去。”6. 正確答案為C 項(xiàng)。四個(gè)選項(xiàng)都是情態(tài)動(dòng)詞的否定表達(dá)。其中，dont have to 表示“不必”；may not 表示“可能不”；mustnt 表示“一定不”；could