2021届高考英语通用版一轮复习考点专讲：考点11完成时学案

考点11 完成时

高考频度：★★★★★
考向一、 现在完成时
1. 现在完成时结构：
主语 + 助动词have(has) + 动词过去分词
否定句：have/has后加not, haven’t/hasn’t
一般疑问句：have/has提前
2. 现在完成时的用法：
（1）表示过去发生的某一动作对现在造成的影响或产生的结果，强调的是这个结果或影响，常与yet，already，just，before，lately等时间状语连用。
—Have you had your lunch yet? 你吃过午饭了吗？
—Yes, I have. I have just had it. 是的，我刚吃过。（现在我不饿了。）
I have already posted the photos. 我已经寄过这些照片了。（这些照片已不在我这里了。）
have(has) gone to，have(has) been to和have(has) been in的区别
1. have (has) gone to表示＂已经去某地了＂，不能与for+一段时间连用。
She has gone to Shanghai.（她可能已在去上海的路上，或已到上海，总之现在不在这里。）
2. have (has) been to表示＂曾经去过某地＂，不能与for+一段时间连用。
She has been to Shanghai three times.（她已经不在上海，只说明她曾经去过。）
3. have (has) been in/at表示＂一直待在某地＂，常与时间段搭配，指待了很久。
（2）过去发生的事情，一直持续到现在（其谓语动词多是延续性动词或表示状态的词）。
I haven’t seen her these days. 近来我一直没见过他。
I’ve known Li Lei for three years. 我认识李雷已经三年了。
They have lived here since 1996. 他们自从1996年就住在这儿。
She has taught us since I came to this school. 自从我来这所学校，她就教我。
3. 现在完成时多与下列时间状语连用：
（1）用于＂过去发生的事，对现在造成的影响或结果＂的时间状语有：
already
用于肯定句，可放在助动词之后、过去分词之前，也可放在句末。
yet
用在疑问句中意为＂已经＂，用在否定句中表示＂还＂，常放在句末。
ever
意为＂曾经＂，用于疑问句或否定句中，放在助动词与过去分词之间。
never
意为＂从来都没有＂，常和before连用，多放在助动词与过去分词之间。
before
意为＂以前＂，指过去不确定的某个时间，总是放在句末，不受句型的限制。
（2）用于＂过去发生的事，一直延续到现在＂的时间状语有：
for + 时间段 for two years
since + 时间点 since 2008
since then
since he came here
so far 目前；迄今为止
up to now=till now=by now 到现在为止；直到现在
all the time 总是；一直
recently/lately 最近
these days 近几天
by the end of...到……末/结束 by the end of this month/year 到本月/年末
during /over the last (past) few years 在过去的几年中
in the last /past days/ months/ years 在过去的几个天/月/年中
（3）在条件、时间、让步状语从句中，表示将来某时以前已完成的动作。
I will not believe you unless I have seen it with my own eyes.
I will go with you as soon as I have finished my work.
（4）非延续性动词的否定形式可以与表示一段时间的状语连用即动作不发生的状态是可以持续的。
I haven’t received his letter for almost a month.
（5）since与for用法比较

用法
例句
since
用来说明动作起始时间
I have lived here since I was born. 我从出生起就住在这里。
My aunt has worked in a clinic since 1949. 我姑姑从1949年开始一直在一个小诊所工作。
for
用来说明动作延续时间长度
I have lived here for more than twenty years. 我在这里住了二十多年了。
3. 现在完成时的常用固定句型
（1）That/This/It is the first (second, third ... ) time... (that) ...句型中，从句要用现在完成时。
It is the first time that I have visited the city. 这是我第一次参观这座城市。
It is the third time that the boy has been late. 这是这个男生第三次迟到了。
（2）＂That/This/It is the + 形容词最高级 + 名词 + （that）从句＂中，that 从句要用现在完成时。
This is the best film that I’ve (ever) seen. 这是我看过的最好看的电影。
（3）在＂It is/has been + 一段时间 + since ... ＂句型中，主句常用现在完成时或一般现在时，从句用一般过去时。
It has been/ It’s 5 years since we last met. 自从上一次我们见面到现在已经是五年了。
It’s / It has been 3 months since the man died. 那人死去3个月了。
（4）一段时间+ 完成时结构+ since 引导的时间状语从句
Two years has passed since I came here. 我来这儿已经两年了。
误区提醒
（1）并非有for 作为时间状语的句子都用现在完成时。
I worked here for more than twenty years. （我现在已不在这里工作）
I have worked here for many years. （现在我仍在这里工作）
（2）短暂性动词和延续性动词用于完成时的区别：
延续性动词表示经验、经历； 短暂性动词表示行为的结果，不能与表示一段时间的状语连用。
He has completed the work. （表结果）
I’’ve known him since then.（表经历）
（3）短暂性动词和延续性动词用于till / until从句的差异
延续性动词用于肯定句，表示＂做……直到……＂；短暂性动词用于否定句，表示＂到……才……＂
He didn’’t come back until ten o’’clock. 直到十点钟他才回来。
He slept until ten o’’clock. 他睡到十点钟。
【疑难辨析】现在完成时和一般过去时的区别
现在完成时表示过去发生的某一动作对现在造成的影响或结果，强调的是现在的情况，所以它不能与表示过去的时间状语连用。如：yesterday, last night, three weeks ago, in 2004 等。
而一般过去时只表示过去的动作或状态，和现在没有任何关系，它可以和表示过去的时间状语连用。
I have seen the film. 我看过这部电影。（我了解这部电影的内容。）
I saw the film last week.我上星期看了这部电影.（只说明上星期看了这部电影，不涉及现在的情况）











1.（2019·新课标II卷·语法填空）I don't see any reason to give up work. I love coming here and seeing my family and all the friends I ___66___(make) over the years
【答案】have made
【解析】考查动词的时态。根据该定语从句中的时间状语“over the years”可知，此处用现在完成时态，句意：我喜欢到这里来看看我的家人和我这些年来交到的朋友们。故填have made。
2.（2018·北京卷·单项填空）China’s high-speed railways _________ from 9,000 to 25,000 kilometers in the past few years.
A. are growing B. have grown C. will grow D. had grown
【答案】B
【解析】考查时态。句意：在过去的几年里，中国的高速铁路已经从9,000公里增长到25,000公里。该句时间状语为in the past few years。中国高速铁路的增长是从过去一直到现在几年里的情况，故该句应用现在完成时态。B选项正确。
3. In the last few years, China __________ great achievements in environmental protection.
A. has made B. had made C. was making D.is making
【答案】A
【解析】句意：在过去的这些年里，中国在环境保护中取得了很大的成就。由时间状语in the last few years可推知动作从过去一段时间持续到现在并对现在造成影响，用现在完成时。故选A。
考向二、 过去完成时
1. 基本结构：
肯定句：主语 + had + 过去分词 + 其他.
否定句：主语 + had + not + 过去分词 + 其他.
一般疑问句：Had + 主语 + 过去分词 + 其他?
特殊疑问句：特殊疑问词或词组 + 一般疑问句（Had + 主语 + 过去分词 + 其他）？
2. 基本用法
（1）表示在过去某一时刻或动作以前完成了的动作，也可以说过去的时间关于过去的动作。即＂过去的过去＂。可以用by，before等介词短语或一个时间状语从句(在复合句中，由时间连接词引导的状语从句叫做时间状语从句)来表示，也可以用一个表示过去的动作来表示，还可能通过上下文来表示。
　　By nine o’clock last night, we had got 200 pictures from the spaceship. 到昨晚9点钟，我们已经收到200 张飞船发来的图片。
（2）表示由过去的某一时刻开始，一直延续到过去另一时间的动作或状态，常和for，since构成的时间状语连用。
　　I had been at the bus stop for 20 minutes when a bus finally came. 当车来的时候，我在车站已经等了20分钟。
　　He said he had worked in that factory since 1949. 他说自从1949年以来他就在那家工厂工作。
（3）叙述过去发生的事情，在已叙述了过去发生的事情后，反过来追述或补述以前发生的动作时，常使用过去完成时。
Mr. Smith died yesterday. He had been a good friend of mine. 史密斯先生昨天去世了。他以前是我的好朋友。
　　I didn’t know a thing about the verbs, for I had not studied my lesson. 我对动词一无所知，因为我没有好好学习功课。
（4）在含有定语从句的主从复合句中，如果叙述的是过去的事，先发生的动作常用过去完成时。
I returned the book that I had borrowed. 我已归还了我借的书。
She found the key that she had lost. 她丢失的钥匙找到了。
（5）过去完成时常常用在told，said，knew，heard，thought等动词后的宾语从句（或间接引语）中，这时从句中的动作发生在主句表示的过去的动作之前。
He said that he had known her well. 他说他很熟悉她。
　　I thought I had sent the letter a week before. 我认为我一星期前就把信寄出去了。
（6）状语从句：在过去不同时间发生的两个动作中，发生在前，用过去完成时；发生在后，用一般过去时。
　　如when，before，after，as soon as，till/until引导的从句。
When I woke up, it had already stopped raining. 我醒来时雨已停了。
She didn’t go to bed until she had finished her work. 她直到把工作做完之后才睡觉。
　　注意：如果两个动作紧接着发生，则常常不用过去完成时，特别是在包含before和after的复合句中，因为这时从句的动作和主句的动作发生的先后顺序已经非常明确，这时可以用一般过去时代替过去完成时。
After he arrived in England, Marx worked hard to improve his English. 马克思到达英格兰之后，努力提高他的英语水平。
（7）动词think，want，hope，mean，plan，intend等用过去完成时来表示过去未曾实现的想法、希望、打算或意图等。
　　They had wanted to help but could not get there in time. 他们本来打算去帮忙，但没有及时赶到那里。
　　We had hoped to be able to come and see you. 我们本来希望能来看看你。
（8）过去完成时还可用在hardly...when...，no sooner... than...，It was the first (second, etc) time (that)...等固定句型中。
Hardly had he begun to speak when the audience interrupted him. 他刚开始演讲，听众就打断了他。
　　No sooner had he arrived than he went away again. 他刚到就又走了。
　　It was the third time that he had been out of work that year. 这是他那一年第三次失业了。
3. 过去完成时的语法判定
（1）由时间状语来判定
一般说来，各种时态都有特定的时间状语。与过去完成时连用的时间状语有：
①by + 过去的时间点
　　I had finished reading the novel by nine o’clock last night.
②by the end of + 过去的时间点
　　We had learned over two thousand English words by the end of last term.
③before + 过去的时间点
　　They had planted six hundred trees before last Wednesday.
（2）由＂过去的过去＂来判定
过去完成时表示＂过去的过去＂，是指过去某一动作之前已经发生或完成的动作，即动作有先后关系，动作在前的用过去完成时，在后的用一般过去时。这种用法常出现在：
①宾语从句中
当宾语从句的主句为一般过去时，且从句的动作先于主句的动作时，从句要用过去完成时。如told，said，knew，heard，thought等动词后的宾语从句。
　　She said that she had seen the film before.
　　②状语从句中
在时间、条件、原因、方式等状语从句中，主、从句的动作发生有先后关系，动作在前的，要用过去完成时，动作在后的要用一般过去时。
　　After he had finished his homework, he went to bed.
注意：before，after 引导的时间状语从句中，由于 before 和 after 本身已表达了动作的先后关系，若主、从句表示的动作紧密相连，则主、从句都用一般过去时。
　　After he closed the door, he left the classroom.
　　③表示意向的动词，如hope, wish, expect, think, intend, mean, suppose等，用过去完成时表示＂原本……，未能……＂。
　　We had hoped that you would come, but you didn’t.
（3）根据上、下文来判定
　　I met Wang Tao in the street yesterday. We hadn’t seen each other since he went to Beijing.
【巧学妙记】
过去完成时记忆口诀
Had 加上＂过去分＂，构成过去完成时。
过去完成的意义，也表＂完成＂或＂延续＂。
若有主、从两个句，先后动作分别叙。
哪个在先哪＂完成＂，哪个在后哪＂过去＂。

1.（2019·天津卷·单项填空）I __________ to send Peter a gift to congratulate him on his marriage，but I couldn't manage it.
A. had hoped B. am hoping
C. have hoped D. would hope
【答案】A
【解析】考查过去完成时。句意：我本来计划在Peter结婚时送他一个礼物的，可是我没有做到。第二个分句中“couldn’t”用的是一般过去时，它之前的动作用过去完成时。故选A。
2. （2018·天津卷·单项填空） If we ___________the flight yesterday, we would be enjoying our holiday on the beach
A. had caught B. caught
C. have caught D. would catch
【答案】A
【解析】考查虚拟语气。句意：如果我们昨天赶上飞机的话，现在我们正在海滩享受我们的假日了。根据时间状语yesterday可知，从句表示与过去事实相反，故用had + v-ed。故选A。
3.（2017·北京卷·单项填空）In the 1950s in the USA, most families had just one phone at home, and wireless phones _______ yet.
A. haven’t invented B. haven’t been invented
C. hadn’t invented D. hadn’t been invented
【答案】D
【解析】句意：在美国20世纪50年代的时候，大多数的家庭家里只有一部电话，并且无线电话还根本没有发明出来。根据句意可知用被动语态，排除A和C，事情发生在过去，与现在无关，不用现在完成时，排除B，故选D，过去完成时的被动语态。
考向三、将来完成时
1. 将来完成时的构成：＂will/shall + have + 过去分词＂。
Hopefully after three years at university I will have matured. 希望3年大学生活之后我能变成熟。
Only five short years later, your money will have grown by $94,000. 仅短短 5 年时间后，你的钱就会增多 94,000 美元。
He will have been heartened by the telephone opinion poll published yesterday. 他会为昨天公布的电话民意调查结果感到鼓舞。
2. 将来完成的用法
（1）表示＂将来完成＂：即表示到将来某个时间为止势必会完成或预计要完成的动作。
When we get there, she’ll have gone to work. 我们到那里时她会已经上班去了。
I expect you will have changed your mind by tomorrow. 我预料到明天你就会改变主意了。
（2）表示＂持续＂：即表示某种状况将一直持续到说话人所提及的某一将来时间。
We will have been married a year on June 25th. 到6月25日我们俩就结婚满1年了。
By this time next week, I will have been working for this company for 24 years. 到下星期此刻，我就已经为该公司工作24年了。
（3）表示＂推测：即表示根据某情况作出的推测。
That will have been Roland. He said he’d be back at 7. 准是罗兰。他说他7点钟回来。
There will have been a definite result before Friday. 星期五以前肯定会有结果。

1.（2019·江苏卷·单项填空）They are trying to make sure that 5G terminals_________ by 2022 for the Beijing Winer Olympics.
A. will install B. will have been installed
C. are installed D. have been installed
【答案】B
【解析】考查时态和语态。句意：他们正努力确保在2022年北京冬奥会之前安装5G终端。表示在将来某一时间以前已经完成或一直持续的动作，用将来完成时。“5G终端”和“安装”之间是被动关系，用被动语态，故选B。
2.It’s reported that by the end of the month, the output of cement in the factory___________by about 10%.
A. will have risen B. will be rising
C. has risen D. has been rising
【答案】A
【解析】考查时态。由时间状语"by the end of the month"可知此处表示在将来某时已经完成的动作，因此用将来完成时。
3.You needn’t hurry her. It___________by her by the time you are ready.
A.will have been finishing B.has finished
C.will have been finished D.will be finished
【答案】C
【解析】考查时态和语态。"by the time you are ready"表示将来的某个时间，此处表示将来完成的动作，故应使用将来完成时，根据句意，事情应该被完成，所以C项正确。

题组一 基础过关
单项填空
1. I ____________ half of the English novel, and I’ll try to finish it at the weekend.
A. read B. have read C. am reading D. will read
2. Silk __________ one of the primary goods traded along the Silk Road by about 100 BC.
A. had become B. was becoming
C. has become D.is becoming
3. —Did you have difficulty finding Ann' house?
—Not really. She________ us clear directions and we were able to find it easily?
A. was to give B. had given
C. was giving D. would give
4. Just as I got to the school gate, I realised I ________ my bank in the cafe.
A. have left B. had left
C. would leave D. was leaving
5. The reports went missing in 2012 and nobody ________ them since.
A. sees B. saw
C. has seen D. had seen
6. When I first met Bryan I didn't like him, but I ________my mind.
A. have changed B. change
C. had changed D. would change
7. Alan Greenspan, once reported as a financial god, had to admit that he ____________ some serious mistakes.
A. made B. had made
C. has been making D. has made
8. James left his hometown when he was 16, and he ____________ back there since.
A. wouldn’t be B. hasn’t been
C. hadn’t been D. won’t be
9. On the morning of October 12, 1492, Christopher Columbus and his crew came to the shores of the Caribbean islands, mistakenly believing they ____________ in Southeast Asia.
A. arrived B. had arrived
C. has arrived D. would arrive
10. Since late 2013 when the Chinese government relaxed the family planning policy, only 1.5 million couples ____________ to have a second child.
A. applied B. had applied
C. would apply D. have applied
题组二 能力提升
阅读下面材料，在空格处填入1个适当的单词或括号中单词的正确形式
Is there such a thing as being ＂over-protective＂?
I can honestly say that my answer to that question 1 (change) dramatically（戏剧性地）since I became a parent.
Before the birth of my daughter, I taught at 2 private school, often viewing my students as over-protected, worrying 3 would happen when they went on to middle schools.
Some did fine, and some did not. Some needed constant pats on the back, words of 4 (encourage) and extra support, which I 5 (happy) gave. Others were content on their own, needing little or no interaction（互动）with their teacher. 6 for the most part, graduates would go on for higher schooling.
I’d always supposed their parents were over-protective, for they were the ones that still walked their 7 (five) graders into the classroom and met them at the school gate.
Admittedly, I laughed at those parents, 8 (think) their children would never learn to be 9 (independence) if they didn’t let go just a little. Then I had my own daughter. The moment I looked at her little face, I 10 (know) I’d do everything in my power to protect her and make sure she always felt safe!

题组三 体验真题
1.（2019·江苏卷·单项填空）The musician along with his band members ___________ ten performances in the last three months.
A. gives B. has given C. have given D. give
2.（2018·江苏卷·单项填空） I was sent to the village last month to see how the development plan _______ in the past two years.
A. had been carried out B. would be carried out
C. is being carried out D. has been carried out
3. （2018·北京卷·单项填空）A rescue worker risked his life saving two tourists who _________ in the mountains for two days.
A. are trapping B. have been trapped
C. were trapping D. had been trapped
4.(2018·新课标卷I·语法填空) Diets have changed in China — and so too has its top crop. Since 2011,the country ___61___（grow）more corn than rice.
5. (2018·浙江卷·语法填空) While regularly eating out seems to 61 (become) common for many young people in recent years, it’s not without a cost.
6.（2017·新课标II卷改编）Around 100 people _________（put down） a $10,000 deposit to get a Transition when they go on sale, and those numbers will likely rise after Terrafugia introduces the Transition to the public later this week at the New York Auto Show.
7.（2017·新课标II卷改编）It _________(white-paint)tunnels and bright red carriages, and proved extremely popular with the public.
8. （2017·新课标III卷改编）The Intelligent Transport team at Newcastle University _________(turn) an electric car into a mobile laboratory named ＂DriveLAB＂ in order to understand the challenges faced by older drivers and to discover where the key stress points are.
9.(2016·天津卷·单项填空) When walking down the street, I came across David, when I _____ for years.
A. didn’t see B. haven’t seen
C. hadn’t seen D. wouldn’t see
10.（2018·江苏卷·单项填空） Hopefully in 2025 we will no longer be e-mailing each other, for we _______ more convenient electronic communication tools by then.
A. have developed B. had developed
C. will have developed D. developed



题组一 基础过关
单项填空
1.B 【解析】句意：我已经看完了这本英文小说的一半，周末会尽力把另一半看完。强调过去发生的动作对现在产生的影响，要用现在完成时。＂看小说＂这一动作发生在过去，到目前为止看了一半，故用现在完成时，选B。
2.A 【解析】句意：到公元前100年为止，丝绸已经成为丝绸之路上交易的主要商品之一。题干中时间状语是by+过去时间，谓语用过去完成时。故选A。
3.B【解析】句意：——你觉得找到安娜家的位置困难么?——不会。她告诉我们很清晰的方向，并且我们很容易就找到了。根据题干可知，安娜告诉他们方向发生在他们找到她家之前，因此，发生在过去动作之前的动作要用过去完成时。故选B。
4.B 【解析】句意：我刚一到学校门口，就意识到我把书落在餐馆了。分析句子结构可知，realized后省略了that，这里是一个宾语从句，从句时态与主句保持一致，“落下”的动作发生在“意识到”之前，应该用过去完成时，故选B。
5.C 【解析】考查动词时态。句意：那些报告于2012年丢失了，从那以后没有人见过它们。此题解题的关键词是后面的since，此处意为：从那以后。这是现在完成时的标志。故选C。
6.A 【解析】本题考查动词的时态。题干中的but提示：“我”第一次见到布莱恩的时候不喜欢他，但现在喜欢他。故用现在完成时，选A。句意：当我第一次见布莱恩的时候我不喜欢他，但我改变想法了。
7. B 【解析】句意：曾经被报道为金融之神的艾伦·格林斯潘不得不承认他之前也犯过一些严重的错误。该空动作发生在主句动作＂had to admit＂之前，应用过去完成时。故选B项。
8. B 【解析】句意：詹姆斯在16岁时离开了家乡，自从那时他就没有回来过。A. wouldn’t be 过去将来时；B. hasn’t been现在完成时；C. hadn’t been 过去完成时；D. won’t be 一般将来时。since是现在完成时的标志。故选B。
9. B 【解析】考查动词的时态。句意：在1492年10月12的早上，克里斯多弗﹒哥伦布和他的船员来到加勒比海岸，误认为他们已经到达了东南亚。强调到达的动作的完成所产生的影响或结果＂mistakenly believing（误认为）＂，且arrive发生在过去的过去，要用过去完成时，故选B。
10. D 【解析】考查动词时态。自从2013年底中国政府放松了计划生育政策，只有150万夫妇已经申请了二孩。since自从……以来，主句要用现在完成时态，故选D。
题组二 能力提升
【文章大意】作者一直都认为现在很多孩子都被父母过度保护，但是在自己的女儿出生以后，他的观点发生了变化，他愿意做一切自己能做的来保护孩子。
1.has changed
【解析】考查时态。本句的时间状语since I became a parent，而since引导时间状语时，主语应该使用现在完成时。故填has changed。
2. a
【解析】考查冠词。句意：在女儿出生之前，我在一所私立学校教书。本句中名词school（学校）是一个可数名词，前面加a表示泛指。
3. what
【解析】考查宾语从句。本句中what引导宾语从句＂what would happen＂作动词worry的宾语，并在句中作主语。
4. encouragement
【解析】考查名词。横线前面有介词of，说明横线上应该使用名词作宾语，动词encourage的名词是encouragement。
5. happily
【解析】考查副词。在英语中副词通常作状语修饰形容词、副词或动词，形容词通常作定语或表语修饰名词。本句中使用副词happily作状语修饰动词give。
6. But
【解析】考查连词。虽然有人需要鼓励，有人不需要鼓励，但是大部分人都要进入更高一级的学校学习。上下文之间表示转折关系，使用but连接上下文。
7. fifth
【解析】考查序数词。本句中the fifth graders指五年级的学生。很多父母亲还陪着五年级的学生上学。
8. thinking
【解析】考查分词作状语。本句中动词think与句子主语I之间构成主动关系，所以使用现在分词在句中作状语。句意：我嘲笑那些父母亲，认为他们的孩子永远都无法学会独立。
9. independent
【解析】考查形容词。本句中形容词independent与be连用构成不定式作动词learn的宾语。句意：我嘲笑那些父母亲，认为他们的孩子永远都无法学会独立。
10. knew
【解析】考查时态。本句的时间状语是the moment I looked at her little face，叙述的是过去发生的事情，所以主句中使用一般过时。
题组三 体验真题
1.B
【解析】考查现在完成时与主谓一致。句意：在过去的三个月里，这名音乐家与他的乐队成员已经完成了十场演出。由“in the last three months”可知，这句话的时态为现在完成时，故排除AD选项。本句主语为the musician，为第三人称单数形式，句中的“along with his band members”是附加成分，故谓语动词要用第三人称单数形式。故选B。
2.A
【解析】考查时态。句意：上个月我被派到村里去看看在过去的两年里发展计划是如何执行的。根据句中时间状语last month和in the past two years可知用过去完成时。故选A。
3. D
【解析】考查语态和时态。句意：一个救援人员冒着生命危险挽救了两个被困在山里两天的旅游者。“who ___ in the mountains for two days”是定语从句，修饰two tourists，two tourists和trap之间是被动关系，该空应用被动语态。由risked可知，营救人员救游客是过去的事情，被困两天发生在营救人员救了他们之前，即“过去的过去”，该空应用过去完成时态。综上，D选项正确。
4.has grown
【解析】考查时态。since加时间点，主句要用现在完成时。句意：2011年以来，中国种植的玉米比水稻多。故填has grown。
5. have become
【解析】考查动词时态。根据时间状语in recent years可知用现在完成时，seems to后用动词原形，故填have become。
6.have already put down
【解析】此处表示动作到现在已完成，强调对现在的影响，故用现在完成时。
7. had white-painted
【解析】此处表示动作发生在过去的过去，故用过去完成时。
8.have turned
【解析】此处表示动作到现在已完成，强调对现在的影响，故用现在完成时。
9.C
【解析】句意：当沿着街道散步的时候，我遇见了多年未见的David。根据语境，“not see”这个动作发生在come across之前，是过去的过去发生的动作，用过去完成时。故选C。
10.C
【解析】考查时态。句意：希望在2025年，我们不再互相发电子邮件，因为到那时候我们将开发更方便的电子通信工具。根据时间状语in 2025，可知用将来时；再根据时间状语by then到那时，可知用完成时。结合两者可知用将来完成时。故选C。