Unit 4 Adversity and Courage
现在完成进行时
一、单项选择
1.For many years, more than one generation of schoolchildren ________ by his bravery and his scientific approach to looking for the truth.
A.have been amazed B.has been amazed
C.was amazed D.were amazed
2.—Have you seen Professor Smith
—He ______ in the lab since yesterday. He doesn’t allow anyone to interrupt him.
A.worked B.was working C.has been worked D.has been working
3.With its magical landscapes, diverse species and mirror-like sky, the Qinghai-Tibet Plateau people’s admiration for centuries.
A.had attracted B.attracted C.attracts D.has been attracting
4.Scientists ______ the ocean currents since last month to better understand their influence on climate patterns.
A.were studying B.had been studying
C.are studying D.have been studying
5.The little boy is dirty from head to foot because he ______ in the garden all morning.
A.had played B.will play C.has been playing D.plays
6.Dr. Li, as well as her parents, ______hard to treat patients and develop medicines over the past two months.
A.are working B.have been working C.has been working D.is working
7.Mary ________ really hard on her book and she thinks she’ll finish it next Friday.
A.worked B.has been working
C.had worked D.has worked
8.—Why is Tony dirty from head to foot
—He ________ in the forest all day!
A.plays B.has been playing C.is playing D.had played
9.The girl has a great interest in sports and _______ badminton classes twice a week over the last three years.
A.have taken B.had been taking
C.have been taking D.has been taking
10.My eyes ache. I _______ in front of the computer all the afternoon.
A.have been stayed B.have been staying
C.has been staying D.had been staying
11.—You look tired.
—Yes, we ______ two rooms since morning and we haven’t finished yet.
A.have painted B.have been painting C.are painting D.painted
12.To find the missing child, villagers________all they can over the past five hours.
A.did B.were doing C.had done D.have been doing
13.I won’t tell the students the answer to the math problem until they on it for more than one hour.
A.have been working B.will be working
C.had worked D.will have worked
14.Mr. Smith ________ these days. I believe it crucial for him ________ a holiday before he reaches a point of burnout.
A.has been overworking; to take B.overworked; taking
C.had overworked; to take D.was overworking; taking
15.—I’m sure Andrew will win the first prize in the final.
—I think so. He ______ for it for months.
A.had been preparing B.is preparing C.has been preparing D.was preparing
16.Many people from Africa ________ hunger and diseases over the past centuries.
A.has suffered B.have been suffered
C.have been suffering from D.suffered from
17.After hearing the terrible news, Linda _______ in her room. No one knows how long it will take her to recover.
A.stayed B.has stayed
C.was staying D.has been staying
18.I ________ Wonder for three months, and ________ 120 pages so far. Hopefully, I will have finished the book by the end of this term.
A.have read; have finished B.have been reading; have finished
C.am reading; have been finishing D.have been reading; finished
19.Judith ________ on her new novel which is supposed to come out next month.
A.has been working B.works C.worked D.had worked
20.She a career change for months but hasn’t made a final decision yet.
A.had considered B.has been considering C.considered D.will consider
21.—I counted sheep, I drank milk and I tried everything, but nothing helped.
—It seems you _______ too much recently. Try some sleeping pills.
A.worked B.work
C.had worked D.have been working
22.I _______ of becoming a professional pianist ever since I was 12.
A.had dreamed B.have been dreaming
C.am dreaming D.dreamed
23.—You look great!
—I _______ out. Check out my muscles!
A.work B.was working
C.have been working D.had been working
24.I'm sure you will do better in the test because you___________ so hard this year.
A.had been studying B.have been studying C.have studied D.studied
25.—I believe that Tom will pass the driving test this time.
—Absolutely. He _______ for the test for the last three weeks.
A.prepared B.will prepare
C.has been preparing D.has prepared
26.Tibetan antelopes________ these passages since they were built.
A.use B.have been using C.used D.was using
27.—Where is Mr. Zhang
—Er..., he headed for the library just now, and________ books there.
A.had been reading B.read C.had read D.has been reading
28.Over the past five years, Martin to teach an endangered language to the next generation despite all the difficulties.
A.will try B.has been trying C.is trying D.was trying
29.He ____ articles for our wall-newspaper these three years, and he _____ about forty articles.
A.has been writing, has written B.has been writing, wrote
C.is writing, has been writing D.has written, has written
30.—Jack, you look so tired!
—Well, I ________ the house all morning and I have to finish the work today.
A.was painting B.will be painting C.painted D.have been painting
二、语法填空
31.She (write) her graduation paper all day long.
32.Mark (work) really hard on his book and he thinks he’ll have finished it by Friday.
33.I (write) the book all year and am hoping to finish it soon.
34.People (bring) their children in to see the hens and residents come and sit outside to watch them.
35.She for the job for months. (apply)
36.They studying for the exam all day. (be)
37.We haven’t decided whether to have a second child. We (think) about it the whole year.
38.It seems that the water from this tap (run) for some time. We have to take it apart to put it right.
39.Ι (wrestle) with this physics problem for a whole morning, but I haven’t worked it out.
40.The fans (wait) for the famous star for 3 hours.
41.Geneticists (try) to identify which genes relate to which diseases, as they believe genome editing is an effective means of disease treatment and prevention.
42.The young man (use) the computer since he was a kid.
43.New recruits (undergo) training in recent weeks.
44.The Boys and Girls Club which he started in Chicago (help) young people since 1996.
45.He (write) articles for our wall newspaper these three years, and he has written about thirty articles.
46.Housing prices (increase) since the end of last year. Therefore, it’s time the central government took measures to bring them under control.
47.Mary (read) this book and thinks she’ll finished it by Friday.
48.Since that unfortunate accident last week I (sleep) badly.
49.I (do) my homework since this morning.
50.In the past one hour, the fire (extend) almost to the top floor, with residents crowding into roof exit.
51.Many scientists say that the number of wild animals (be) getting smaller and smaller in the past few years.
52.Why are you so late I (wait) for you for three hours.
53.People (pour) into stadiums for various reasons since the days of ancient Greece.
54.It's hard to tell exactly how many people agree with him, but research indicates that the numbers (rise) for some time.
55.“Your child (look) for an opportunity to climb out of the window all day long,” the man said as he gave the child back to her.
试卷第11页,共33页
参考答案:
1.B
【详解】考查时态和主谓一致。句意:多年来,不止一代的学生对他的勇敢和他寻找真理的科学方法感到惊讶。根据时间状语For many years可知,用现在完成时;“more than one + 单数名词”作主语时,谓语动词要用单数形式。故选B。
2.D
【详解】考查动词时态。句意:——你见过史密斯教授吗?——他从昨天起就一直在实验室工作。他不允许任何人打扰他。根据“since yesterday”和“He doesn’t allow anyone to interrupt him.”可知,work“工作”这一动作开始于过去,持续到现在,并将继续持续下去,由此可知,句子应用现在完成进行时,结构为have/has been doing,又因主语是第三人称单数代词,所以助动词用has。故选D项。
3.D
【详解】考查时态。句意:几个世纪以来,青藏高原以其神奇的风景、多样的物种和镜子般的天空吸引着人们的崇拜。attract是句中谓语动词,结合时间状语for centuries可知,描述从几个世纪前一直持续到现在的动作,可用现在完成时态或现在完成进行时态。结合选项,D项符合语境。故选D项。
4.D
【详解】考查时态。句意:自上个月以来,科学家们一直在研究洋流,以更好地了解它们对气候模式的影响。根据后文since last month可知,表示动作从某一时间开始,一直不间断持续到现在,可能仍然要继续下去,应用现在完成进行时。故选D。
5.C
【详解】考查时态和主谓一致。句意:这个小男孩从头到脚都很脏,因为他整个上午都在花园里玩。A. had played过去完成时;B. will play一般将来时;C. has been playing现在完成进行时;D. plays一般现在时。 根据时间状语all morning可知,空处描述某动作从过去某个时间开始,一直延续到现在,并且还有可能持续下去,应用现在完成进行时。主语是he,助动词使用has。故选C项。
6.C
【详解】考查时态及主谓一致。句意:在过去的两个月里,李医生和她的父母一直在努力治疗病人和开发药物。该空动词work在句子作谓语,根据时间状语over the past two months可知,应该使用现在完成时会现在完成进行时,主语Dr. Li为单数人称,as well as her parents为插入语,her parents不是主语,所以谓语动词应使用单数形式。故选C项。
7.B
【详解】考查动词时态。句意:玛丽非常努力地写她的书,她认为她下星期五就能完成。分析语境可知,and之后的句子“she’ll finish it next Friday”表明书还未写完,从而推知Mary“写书”这个动作应该是从过去到现在一直进行的动作,并且还会持续下去,所以为现在完成进行时。故选B项。
8.B
【详解】考查时态。句意:——为什么托尼从头到脚都脏?——他在森林里玩了一整天!根据问句“Why is Tony dirty from head to foot ”和答句中的“all day”可知,这里应用现在完成进行时,表示动作从过去某时开始一直持续到现在,而且还有可能继续下去。故选B。
9.D
【详解】考查时态和主谓一致。句意:这个女孩对运动很感兴趣,在过去的三年里,她每周上两次羽毛球课。由over the last three years及这个女孩可能会继续上羽毛球课,因此空格处时态用现在完成进行时,表示从过去进行到现在,且有可能继续下去的动作,主语girl是单数,因此空格处是has been taking。故选D。
10.B
【详解】考查动词时态。句意:我的眼睛疼。我整个下午都呆在电脑前。根据时间状语all the afternoon和ache可知,动作stay“停留,呆着”从过去开始并且一直在发生到现在,句子时态要用现在完成进行时,构成为have/has been doing,主语为I,故助动词用have。故选B。
11.B
【详解】考查时态。句意:——你看起来很累。——是的,从早上开始我们已经粉刷了两个房间,但还没有完成。分析句子可知,这里考查谓语,we和paint为主动关系,且由since以及we haven’t finished yet可知,这里时态应用现在完成进行时,表示动作从过去某一时间开始,一直持续到现在,或者可能仍然要继续下去。故选B项。
12.D
【详解】考查时态。句意:为了找到失踪的孩子,村民们在过去的五个小时里一直在竭尽全力。根据时间状语“over the past five hours”可知,此处表示过去的一段时间内一直持续进行的动作,应该用现在完成进行时。故选D。
13.A
【详解】考查动词时态。句意:直到他们一直做了一个多小时后,我才告诉学生们这道数学题的答案。分析句子结构可知,此处应为谓语动词,根据主将从现原则,until引导的时间状语从句中应用现在时态,结合句意以及时间状语for more than one hour可知,work on这一动作持续了一段时间且一直在进行,所以应使用现在完成进行时,句子主语为第三人称复数they,所以应为have been working。故选A项。
14.A
【详解】考查时态和非谓语动词。句意:史密斯先生这些天一直在过度工作。我认为在他达到疲劳极限之前休假是至关重要的。根据时间状语 these days 可知,此处用现在完成进行时,强调动作的持续性;it is crucial for sb. to do sth.做某事对某人至关重要,it 是形式宾语,不定式是真正的宾语。故选 A。
15.C
【详解】考查时态。句意:──我相信安德鲁会在决赛中获得一等奖。──我想是的。他已经准备了好几个月了。Andrew是从过去到现在一直在准备,用现在完成进行时,故选C。
16.C
【详解】考查时态。句意:在过去的几个世纪里,许多非洲人饱受饥饿和疾病之苦。根据后文over the past centuries可知为完成时,故排除D选项;且表示“遭受”短语为suffer from,故排除A、B选项。故选C。
17.D
【详解】考查时态。句意:听到这个可怕的消息后,琳达一直待在她的房间里。没人知道她需要多长时间才能恢复过来。分析句子结构可知,此处为谓语动词,根据句意和下文中的“No one knows how long it will take her to recover.”可知,听到可怕的消息后琳达就待在房间,表示动作从过去持续到现在,且强调动作一直正在进行,应用现在完成进行时,谓语动词为has been staying。故选D项。
18.B
【详解】考查动词时态。句意:我读《奇迹》已经三个月了,到目前为止已经读了120页。希望在这学期末我能读完这本书。分析句子结构可知,本句是and连接的并列句,read作前句谓语,根据时间状语for three months可知,用完成时,根据句意,还没读完,这个动作一直在进行,用现在完成进行时,finish作后句谓语,根据so far可知,用现在完成时。故选B项。
19.A
【详解】考查时态。句意:朱迪思一直在写她的新小说,这本小说须下个月出版。根据句中的which is supposed to come out next month可知,她的小说还没写完,现在还在写,此处表示从过去一直到现在一直在写,可能还会写下去,应使用现在完成进行时。故选A。
20.B
【详解】考查动词时态。句意:几个月来她一直在考虑换工作,但还没有做出最后决定。根据“but hasn’t made a final decision yet”可知,consider“考虑”这一行为从过去开始,一直持续到现在,且可能持续下去,因此用现在完成进行时。故选B。
21.D
【详解】考查时态。句意:——我数羊,喝牛奶,什么都试过了,但都没用。——你最近好像工作太忙了。试试安眠药。根据后文recently可知表示动作从某一时间开始,一直持续到现在,并可能会一直延续下去,应用现在完成进行时。故选D。
22.B
【详解】考查时态。句意:我从12岁起就一直梦想着成为一名专业钢琴家。设空处为谓语,根据时间状语ever since I was 12可知设空处应用完成时,并且这个梦想还有可能一直持续下去,应用现在完成进行时。故选B。
23.C
【详解】考查现在完成进行时。句意:——你看起来棒极了! ——我一直在健身。看看我的肌肉!前句“你看起来棒极了”,说明身材很好,一直在健身;表示从过去开始到现在一直进行的动作用现在完成进行时。故选C。
24.B
【详解】考查动词的时态与语态。句意:我相信你会在测试中做得更好,因为你今年一直很努力。根据句子语境及 this year,可知此处表达“作者一直学习很努力”,结合前面主句时态为一般现在时,可知此处用现在完成进行时。选项B. have been studying符合题意,故选B。
25.C
【详解】考查时态。句意:——我相信汤姆这次会通过驾驶考试的。——当然。过去三周他一直在为考试做准备。根据“Tom will pass the driving test this time”和时间状语“for the last three weeks”可知,此处表示prepare“准备”的行为从过去一直持续到现在,且很有可能持续下去,因此时态应用现在完成进行时,空处应用has been preparing。故选C。
26.B
【详解】考查动词时态。句意:自这些通道建成以来,藏羚羊就一直在使用这些通道。分析句子结构可知,根据标志词since,应用现在完成时,根据句意,描述的是在使用,表示动作还将持续下去,所以此处用现在完成进行时。故选B项。
27.D
【详解】考查动词时态。句意:——张先生在哪里?——呃……,他刚才去了图书馆,一直在那儿看书。分析句子结构可知,此处应为谓语动词,结合语境可知,此处询问Mr. Zhang现在在哪里,所以应使用现在时态,结合答语中的“他刚去图书馆了”,由此可知,Mr. Zhang应该是从去图书馆开始到现在一直在图书馆读书,故使用现在完成进行时,且句子主语为第三人称单数,此处应为has been reading。故选D项。
28.B
【详解】考查动词时态。句意:在过去的五年里,尽管困难重重,马丁一直在努力向下一代教授一门濒危语言。分析句子可知,此处为谓语动词的填入,结合句意以及时间状语Over the past five years可知,此处应为现在完成进时,表示“表示动作从过去某一时间开始,一直持续到现在,或者刚刚终止,或者可能仍然要继续下去”。故选B项。
29.A
【详解】考查动词时态和主谓一致。句意:这三年来,他一直在为我们的板报写稿,他已经写了大约四十篇文章。分析句子结构可知,两空均为谓语动词,根据句意以及时间状语these three years可知,第一空表示“这三年他一直写稿”,应用现在完成进行时,write与句子主语he之间为主动关系,且句子主语为第三人称单数,所以第一空为has been writing;结合上文可知,“他一直给板报写稿”,所以此处表示该动作从过去开始到现在为止已完成的动作,应使用现在完成时,write与句子主语之间为主动关系,主语为第三人称单数,所以第二空为has written。故选A项。
30.D
【详解】考查时态。句意:——杰克,你看起来太累了!——嗯,我整个上午都在粉刷房子,今天我必须完成这项工作。分析句子可知,这里考查时态,I 和paint为主动关系,由you look so tired以及 I have to finish the work today可知,这里时态应用现在完成进行时,表示动作从过去某时开始,一直延续到现在,将来还可能延续下去,强调动作的延续性。故选D项。
31.has been writing
【详解】考查时态。句意:她一整天都在写毕业论文。根据时间状语all day long可知,用现在完成进行时,表示动作从过去某个时间开始,一直延续到现在,并且还有可能持续下去。主语是she,谓语动词用第三人称单数形式。故填has been writing。
32.has been working
【详解】考查动词时态。句意:马克一直在努力写他的书,他认为他会在星期五之前完成。分析句子结构可知,此处应为谓语动词,根据句意以及下文中的“he thinks he’ll have finished it by Friday.”可知,Mark应该是在过去开始写书,一直写到现在,将在星期五完成,所以此处使用现在完成进行时,且与句子主语Mark之间为主动关系,且主语为第三人称单数。故填has been working。
33.have been writing
【详解】考查时态。句意:这本书我写了一整年,希望很快写完。write是谓语动词,结合all year可知,用现在完成进行时表示“写”的动作从过去一直持续到现在可能还在继续,强调其动作的延续。故填have been writing。
34.have been bringing
【详解】考查时态。句意:人们一直带着孩子来看母鸡,居民们也来坐在外面看。bring谓语动词,表示此动作从过去某个时间开始,一直延续到现在,并且还有可能持续下去,强调动作的延续性,用现在完成进行时,主语是复数,助动词使用have。故填have been bringing。
35.has been applying
【详解】考查现在完成进行时。句意:她申请这份工作已经好几个月了。根据句意以及该句for months时间状语可知,此处为现在完成进行时,表示“动作从过去某一时间开始,一直持续到现在,或者刚刚终止,或者可能仍然要继续下去”,为have/has been doing形式。结合主语She为第三人称单数,所以为动词三单形式。故填has been applying。
36.have been
【详解】考查现在完成进行时。句意:他们为考试学习了一整天。根据时间状语all day可知,此处表示从过去某时的动作一直持续到现在,并有可能继续持续下去,应用现在完成进行时,其结构为“主语+have/has been doing”。主谓一致,故填have been。
37.have been thinking
【详解】考查动词时态。句意:我们还没有决定是否要第二个孩子。我们一整年都在考虑这件事。根据语境可知,此处表示动作从过去一直持续到现在,还有可能持续下去,应用现在完成进行时,主语是we,助动词使用have。故填have been thinking。
38.has been running
【详解】考查时态和主谓一致。句意:这个水龙头的水好像已经流了一段时间了。我们必须把它拆开才能纠正。根据空后的“for some time”和句中的“We have to take it apart to put it right”可知,这里应用现在完成进行时,表示从过去某一时间一直持续到现在,而且有可能继续下去的动作。主语the water为不可数名词,所以谓语应用单数。故填has been running。
39.have been wrestling
【详解】考查动词时态。句意:我整个上午都在努力解决这个物理问题,但还没有算出来。分析句子结构可知,此处为谓语动词,根据句意和时间状语“for a whole morning”可知,此处应使用现在完成进行时,表示该动作从过去开始一直持续整个上午,可能还要持续下去,wrestle与句子主语I之间为主动关系。故填have been wrestling。
40.have been waiting
【详解】考查时态和主谓一致。句意:影迷们等那位明星已经等了3个小时了。由for 3 hours可知,句子表示一个动作从过去持续到现在,且还可能继续下去,因此空格处用现在完成进行时,主语fans是复数,因此空格处是have been waiting。故填have been waiting。
41.have been trying
【详解】考查谓语动词的时态和语态。句意:遗传学家一直在试图确定哪些基因与哪些疾病有关,因为他们认为基因组编辑是治疗和预防疾病的有效手段。设空处为句子的谓语,根据“as they believe genome editing is an effective means of disease treatment and prevention.(因为他们认为基因组编辑是治疗和预防疾病的有效手段)”可知,因为他们认为基因组编辑是治疗和预防疾病的有效手段,所以他们一直在试图确定哪些基因与哪些疾病有关,设空处表示从过去一直持续到现在的动作,应用现在完成进行时,主语为Geneticists,结合主谓一致。故填have been trying。
42.has been using/has used
【详解】考查时态和主谓一致。句意:这个年轻人从小就一直在用电脑。根据时间状语“since he was a kid”可知,此处可用现在完成进行时,表示从过去某时开始一直持续到现在的动作,并且还将持续下去;也可用现在完成时;主语man是名词单数,助动词用has,故填has been using/has used。
43.have been undergoing
【详解】考查现在完成进行时。句意:新兵们最近几周一直在接受训练。根据句意和时间状语in recent weeks可知,此处表示动作发生在过去,持续到现在,并有可能一直持续下去,应用现在完成进行时,主语是复数名词,助动词用have。故填have been undergoing。
44.has been helping
【详解】考查动词时态。句意:他在芝加哥创办的男孩女孩俱乐部自1996年以来一直在帮助年轻人。分析句子可知,设空处是句子谓语部分,根据时间状语since 1996可知,应使用现在完成进行时,表示一直在做,主语The Boys and Girls Club是专有名词,第三人称单数形式,助动词应使用has。故填has been helping。
45.has been writing
【详解】考查动词时态和主谓一致。句意:这三年来,他一直在为我们的日报写文章,他已经写了大约三十篇文章。根据时间状语“these three years”和“and he has written about thirty articles”可知,此处表示一个动作从过去开始持续到现在并将持续下去,使用现在完成进行时,主语为he,助动词用has。故填has been writing。
46.have been increasing
【详解】考查动词时态。句意:房价自去年底以来一直上涨。因此,现在是中央政府采取管控措施的时候了。分析句子可知,设空处是句子的谓语部分,根据句意以及时间状语since the end of last year可知,房价还有可能持续上涨,此处应使用现在完成进行时,主语Housing prices是复数形式,故填have been increasing。
47.has been reading
【详解】考查动词时态。句意:玛丽一直在读这本书,她想她星期五就能读完。分析句子可知,设空处是句子的谓语部分,根据句意可知,玛丽“读这本书”的动作从过去持续到现在且还会一直读下去,应使用现在完成进行时,主语是第三人称单数形式,故填has been reading。
48.have been sleeping
【详解】考查时态。句意:自从上周那次不幸的事故以来,我一直睡得不好。根据上文Since that unfortunate accident last week可知表示动作从某一时间开始,一直持续到现在,或者可能仍然要继续下去,应用现在完成进行时,主语为I,助动词用have。故填have been sleeping。
49.have been doing
【详解】考查动词时态。句意:从今天上午起我就一直在做作业。根据句意以及句中since this morning时间状语可知,此处应为现在完成进行时,表示“动作从过去某一时间开始,一直持续到现在,或者刚刚终止,或者可能仍然要继续下去”。故填have been doing。
50.has been extending
【详解】考查时态。句意:在过去的一个小时里,火势几乎蔓延到了顶楼,居民们纷纷涌入屋顶的出口。此处是谓语,由In the past one hour和句意可知,此处表示从过去到现在一直在蔓延,强调动作的持续性,应用现在完成进行时,主语是the fire,助动词应用has,故填has been extending。
51.has been
【详解】考查时态。句意:许多科学家说,在过去的几年里,野生动物的数量越来越少。根据时间状语in the past few years并结合语意可知,that引导的从句应用现在完成进行时,表示动作从过去持续到现在,且这一动作在这一阶段是一直正在进行的,主语为“the number of+复数可数名词”,谓语动词应用第三人称单数形式,即has been getting。故填has been。
52.have been waiting
【详解】考查时态。句意:你为什么这么晚?我已经等你三个小时了。分析句子结构可知,空处为句子的谓语动词。根据for three hours可知,本句话用现在完成进行时态,强调动作的持续性,主语为I,助动词用have。故填have been waiting。
53.have been pouring
【详解】考查时态。句意:从古希腊时代起,人们就因各种原因涌入体育场。由时间状语since the days of ancient Greece可知动作发生在过去,持续到现在,且还会持续下去,故用现在完成进行时,主语为people,助动词用have。故填have been pouring。
54.have been rising
【详解】考查时态和主谓一致。句意:很难确切地说有多少人同意他的观点,但研究表明,这一数字已经上升了一段时间。结合句意及空后的“for some time”可知,此处表示过去发生的事情一直持续到现在,可能还会继续下去,应用现在完成进行时,结构为“have/has been doing”,主语numbers是名词复数,助动词用have,故填have been rising。
55.has been looking
【详解】考查动词的时态。句意:“你的孩子一整天都在找机会从窗户爬出去” 那个男人说着把孩子还给了她。设空处为句子的谓语,根据时间状语all day long,可知,表示从过去到现在一直进行的动作,句子的时态为现在完成进行时,主语为Your child,结合主谓一致。故填has been doing。
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