内容正文:
零基础英语语法“讲-析-练”一遍过
第二章 名词
(
热点用法概述
)第一节 热点用法精讲
众多名词难辨,看名师如何指点。
(
热点用法
诠释
)纵观近五年高考试题不难看出,名词在高考命题中占有一定比例。完形填空和语法填空是名词命题的主要形式。关于名词需要掌握的核心知识点主要有:名词复数的构成,特别是特殊名词复数形式的构成;可数与不可数名词的辨别、抽象名词与物质名词的用法;名词所有格的表达形式;名词用作定语;名词同义(近义)词辨异等。因此在学习和复习中要有针对性地突破和掌握名词的用法。
尚未登台表演,记住台词是关键。
名词可以分为专有名词和普通名词;普通名词又可以分为个体名词、集体名词、物质名词和抽象名词四种。名词的数、名词的所有格和名词作主语时的主谓一致关系是我们复习名词时必须掌握的重点,下面详细阐述与名词相关的问题。
一、可数名词的复数变化
1.规则名词的复数变化:
①一般在名词词尾直接加-s。如:boy→boys, map→maps。
②以s, x, ch, sh等结尾的名词应加-es。如:bus→buses, watch→watches, wish→wishes。
③以y收尾的名词分为两种情况:
a)以“辅音字母+y”结尾的名词,先将y变为i,再加-es。如:family→families;
b) 以y结尾的专有名词,或元音字母+y 结尾的名词变复数时,直接加s变复数。例如:two Marys;the Henrys;monkey→monkeys;holiday→holidays。
另外注意名词“楼层”的复数:storey→storeys,而“故事”的复数:story→stories
④以o 结尾的名词,变复数时:
a)加s。例如:bamboo→bamboos, studio→studios, cuckoo→cuckoos, photo→photos, piano→pianos, radio→radios, zoo→zoos等。
b)加es。例如:potato→potatoes, tomato→tomatoes, hero→heroes, Negro→Negroes等。
c)加s或es均可。例如:zero→zeros/zeroes。
⑤以f或fe结尾的名词复数形式的构成:
a)加s。例如:belief→beliefs, roof→roofs, safe→safes, gulf→gulfs;
b)去f或fe 收尾的名词加ves。例如:half→halves, knife→knives, leaf→leaves, wolf→wolves, wife→wives, life→lives, thief→thieves;
c)按照上述两种方法均可。例如:handkerchief→handkerchiefs/handkerchieves。
2.不规则名词的复数变化:
①将a变成e。例如: man→men, woman→women。注意:与 man 和 woman构成的合成词,其复数形式也是 -men 和-women。例如:an Englishman, two Englishmen. 但German不是合成词,故复数形式为Germans, Bowman是姓,其复数是the Bowmans;
②将oo变成ee。例如: foot→feet, goose→geese, tooth→teeth;
③词尾加-r(en)。例如:child→children, ox→oxen;
④将ou变成i。例如:mouse→mice;
⑤单复数同形。例如:deer, fish, Chinese, Japanese, sheep等。
还有一些表示数量的名词也没有数的变化,例如:li, jin, yuan, two li, three mu, four jin等。但除人民币元、角、分外,美元、英镑、法郎等都有复数形式。例如:a dollar→two dollars, a meter→two meters等。
二、不可数名词的数量的表达
1.物质名词:
①当物质名词转化为个体名词时,该名词可数。试比较:
Cake is a kind of food. 蛋糕是一种食物。 (不可数)
These cakes are sweet. 这些蛋糕很好吃。 (可数)
②当物质名词表示该物质的种类时,名词可数。试比较:
This factory produces steel.这家工厂生产钢材。(不可数)
We need various steels.我们需要各种钢材。(可数)
③当物质名词表示份数时,可数。试比较:
Our country is famous for tea. 我国因茶叶而闻名。(不可数)
Two teas, please.请来两杯茶。(可数)
④抽象名词有时也可数。例如:
four freedoms 四大自由
the four modernizations四个现代化
⑤有些物质名词和抽象名词虽然在汉语里是可数的,在英语中却不可数。例如:news, furniture, bread, information, luggage, clothing, fun, advice, progress, courage, butter, poverty等;但是,这类物质名词和抽象名词可以借助单位词表一定的数量。例如:
a piece of information 一则消息 a piece of advice 一条建议
an article of furniture 一件家具 a lump of sugar 一块糖
三、作主语的名词的复数
1. 不可数名词作主语时,谓语动词用单数形式。例如:
No news is good news.没有消息就是好消息。
2. family, team, class等集合名词作主语时,若强调整体,谓语动词用单数形式;若强调组成集体的各个成员,谓语动词用复数形式。试比较:
His family is a big one. 他家是一个大家庭。
His family are watching TV. 他全家人在看电视。
3. 专有名词复数与定冠词连用,表示“某某夫妇”或“某某一家”,作主语时,用复数。例如:
The Smiths are going to climb Mount Tai next week.史密斯一家将于下周去爬山。
四、用作定语的名词的复数:名词作定语一般用单数,但也有以下例外。
1.用复数作定语。例如:
sports meeting 运动会;students reading-room 学生阅览室; talks table 谈判桌;the foreign languages department 外语系。
2.man, woman, gentleman等作定语时,其单复数以所修饰的名词的单复数而定。例如:men workers, women teachers, gentlemen officials等。
3.有些原有s结尾的名词,作定语时,s保留。例如:goods train (货车);arms produce 武器生产;customs papers 海关文件;clothes brush衣刷。
4.数词+名词作定语时,这个名词一般保留单数形式。例如:two-dozen eggs 两打/(二十四个鸡蛋);a ten-mile walk 十里路;two-hundred trees 两百棵树;a five-year plan. 一个五年计划。
五、特殊名词的数的情况
1.当修饰词不是man或woman时,则只把被修饰的名词变为复数。如:a book store→book stores。
2.如果合成名词中含有主体名词,则一般将主体名词变成复数形式;如果没有主体名词,则把最后一个名词变成复数形式。例如:如:a pencil-box→pencil-boxes, looker-on→ lookers-on, son-in-law→sons-in-law, grand-child→grand-children, go-between→go-betweens等。
3.在作定语的合成词中,名词要用单数形式。例如:a fifteen-year-old boy。
4.表示由两部分构成的东西。例如:glasses (眼镜), scissors, compasses, trousers, clothes等。若表达具体数目,要借助数量词 pair(对,双), suit(套), a pair of glasses, two pairs of trousers。
5.集体名词,以单数形式出现,但实为复数。例如: people, police, cattle 等本身就是复数,不能说 a people, a police, a cattle。但可以说:a person, a policeman, a head of cattle, the English, the British, the French, the Chinese, the Japanese, the Swiss 等名词,表示国民总称时,作复数用。例如:The Chinese are industries and brave.中国人民是勤劳勇敢的。
6.有些名词以s结尾的名词,仍看作单数。例如:
a. maths, politics, physics等学科名词;
b. news 是不可数名词;
c. the United States, the United Nations 应视为单数。例如:The United Nations was organized in 1945. 联合国是1945年组建起来的。
d. 以复数形式出现的书名,剧名,报纸,杂志名,也可视为单数。例如:The Arabian Nights is a very interesting story-book. 《一千零一夜》是一本非常有趣的故事书。
六、名词所有格
1.表示有生命的名词的所有格
①一般在名词的词尾加“’s”来表示。例如:the boy’s desk。
②以s结尾的复数名词只加“’”,不以s结尾的复数名词加“’s”。例如:Teachers’ Day,Women’s Day。
③如果一样东西为几人共有,则在最后一个名词后加“’s”;如果不是共有,则在每一个名词后都加“’s”。例如:Jim’s and Tom’s desks,Lucy and Lily’s mother。
④有些表示时间、距离、国家、城市、团体等无生命的东西,也可以加“’s”构成所有格。例如:today’s newspaper,ten minutes’ walk。
2.表示无生命的名词的所有格:表示无生命东西的名词一般与of构成词组,表示所有关系。例如:the price of the dictionary。
3.双重所有格:在表示所属物的名词前有冠词、数词、不定代词或指示代词(a, two, some, a few, this等)时,常用“of+所有格”的形式来表示所有关系。如:a friend of my father’s)。
(
名
精
典
题
赏析
)第二节 经典好题赏析
看名师潇洒点拨,助力名词难点全突破。
1. You will find this map of great _____ in helping you to get around the city.
A. source B. sense C. favour D. value
[赏 析]be of + 抽象名词这个词组的意思是同抽象名词所对应的形容词的意思。source意思是“来源”;sense是“感觉”;favour是“偏爱”;value是“用途、价值”。根据题意选D。
2. Do you have any _____ of what life would be like if we lived on other planets?
A. plan B. idea
C. impression D. imagination
[赏 析]本题考查名词词义辨析。短语have idea of 相当于know,have no idea of 相当于don’t know。imagination是“想象”;impression是“印象”,后面跟介词on。本题答案是:B。
3. My _____ of this weekend’s activity is going out with some good friends.
A. idea B. opinion C. mind D. thought
[赏 析]本题考查表达“看法”的一组名词的辨析。idea指“意见;想法”,符合本题“对本周活动的意见”,因此A最佳。opinion侧重于“对某事的个人看法;观点”, mind 与thought意思接近,侧重于“思考;思想”。故正确答案是A。
4. He proved himself a true gentleman and the beauty of his _____ was seen at its best when he worked with others.
A. temper B. appearance C. talent D. character
[赏 析]本题考点是近义词的区分。题干的意思是:一个真正的绅士是体现在人格魅力上,而不是体现在脾气上,外表上或智慧上。故此题的正确答案是D。
5. The head office of the bank is in Beijing, but it has _____ all over the country.
A. companies B. branches
C. organizations D. businesses
[赏 析]表达“分支机构”用branches,而companies意思是“公司”,organizations指组织,businesses指贸易。从前面的head office我们知道,这个银行还有分支机构。故正确答案是B。
6. Beginners are expected to be familiar with the _____ of the reading material before they came to the class.
A. condition B. concept C. contest D. content
[赏 析]从后面的“进班之前”提示可以知道,希望初学者能熟悉阅读材料的“内容”,选D。condition是“条件”;concept是“概念”;contest是“竞赛”。
7. The faces of famous American presidents on Mount Rushmore can be seen from a _____ of 60 miles.
A. length B. distance C. way D. space
[赏 析]本题考查由名词构成的词组作定语的用法。a length of意思是“一段多长的东西”;而a distance of意思是“一段多远的距离”是“一段60英里的距离”。本题答案是:B。
8. The village is far away from here indeed. It’s_____ walk.
A. a four hour B. a four hour’s
C. a four hours D. a four hours’
[赏 析]本题考点是名词所有格。当无生命的名词是时间、距离、国家、城镇、天体、团体或机构时,名词后一般加“-’s”构成所有格;如果名词以-s收尾,则只加“’”;另外用作定语的复合形容词,其中的名词要用单数。本题答案是D。
9. —I’m sorry I stepped outside for a smoke. I was very tired.
—There is no _____for this while you are on duty.
A. reason B. excuse C. cause D. explanation
[赏 析]本题考查名词词义辨析。reason意为理由;cause意为原因;explanation意为解释。而excuse意为借口,即为自己辩护而找出的理由。故excuse符合本题题意,正确答案是B。
10. “I don’t think it’s my _____that the TV blew up. I just turned it on, that’s all,” said the boy.
A. error B. mistake C. fault D. duty
[赏 析]本题考查名词词义辨析。error和mistake均意为“错误”;duty意为“责任”;fault意为“过错”,指因犯错误而应负有的责任。根据句义可知,正确答案是C。
11. The _____ is just around the corner and you won’t miss it.
A. bicycle’s shop B. bicycle shop
C. bicycles shop D. bicycles’ shop
[赏 析]本题考查名词所有格和普通格作定语的区别。名词所有格表示所修饰名词的归属;名词普通格作定语则表示被修饰名词的性质、类别、用途或材料,不表示所属关系,如:time table,paper flower,tea pot等。在本题中,“自行车”是说明“商店”的类别。故正确答案是B。
12. No matter what you do. You should put your _____into it.
A. mind B. heart C. brain D. thought
[赏 析]本题考查固定搭配中的名词。put one’s heart into sth.是固定搭配,意为“一心扑在某事上面,专心做某事”。故正确答案是B。
(
全考点精
题
练
)第三节 经典好题专项训练
真题典题模拟题,包你名词用法一遍过。
1. Now our city has _______of more than two million.
A. the population B. a population
C. populations D. population
2. If you don’t take away all your things from the desk, there won’t be enough ______ for my stationery.
A. area B. place C. room D. surface
3. We’re going to drop in at ____.
A. Peter the doctor clinic B. Peter’s the doctor’s clinic
C. Peter’s the doctor clinic D. Peter the doctor’s clinic
4. ____ came that the foreign company would pay for all the ____caused by the quality problems of their equipment.
A. Word; loss B. Words; losses
C. Word; losses D. Words; loss
5.When the girl caught sight of the ___she gave a scream.
A. mice field B. field mice C. field mouses D. mouses field
6.There were six people at the table, and they asked the waiter for ____ and ____.
A. two cups of tea; four coffee
B. two teas; four coffee
C. two teas; four coffees
D. two cup of tea; four cup of coffee
7.If this dictionary is not yours, ____ can it be?
A. what else B. who else
C. which else’s D. who else’s
8.He gained his ____ by printing ___ of famous writers.
A. wealth; work B. wealths ; works
C. wealths; work D. wealth; works
9.It was ___ fun to play on the beach that it attracted countless children.
A. such great B. so great C. such a great D. so great a
10. Don’t leave medicines on the table within ____ of little children.
A. hand B. reach C. space D. distance
11.To my ____, the workers set up a carved figure in front of the building.
A. pleasing B. pleasure C. please D. pleasant
12.I could tell he was pleased from the ____ on his face.
A. sight B. look C. appearance D. shock
13. This book is a ____ for students of university.
A. must B. necessary C. useful D. important
14.She knows that as a secretary she must be pleasant and helpful no matter how busy she is or what kind of ___ she may be in.
A. mood B. mind C. form D. thought
15.The head office of the company is in Beijing, but it has _____ all over the country.
A. companies B. branches C. organizations D. businesses
16.Bill was doing a lot of physical exercise to build up his _____.
A. ability B. force C. strength D. mind
17.My ___ of this weekend’s activity is going out with some good friends.
A. idea B. opinion C. mind D. thought
18.I am sure David will be able to find the library-he has a pretty good ____ of direction.
A. idea B. feeling C. experience D. sense
19. —Would you like ____, sir?
— No, thanks. I have had much.
A. some more oranges B. any more oranges
C. some more orange D. any more orange
20. A ____ will be offered to information leading to the arrest (逮捕) of the bank robber.
A. price B. fund C. reward D. profit
21.The woman in blue is ____ .
A. Lucy and Mary’s mothers
B. Lucy’s and Mary’s mother
C. Lucy’s and Mary’s mothers
D. Lucy and Mary’s mother
22. —What was it, Dad?
—Just a (n) ____. It’s gone now.
A. injury B. ache C. wound D. pain
23.The old woman has so bad a cold that she has lost all ____ of smell.
A. feeling B. sense C. skill D. strength
24.I should like to try that coat on, ____ I don’t know if it is my ____.
A. for; size B. for; design C. but; size D. but; design
25. —The manager ____ me and told me they had no ____ for clerks but a secretary.
—Did you have a try?
A. accepted; jobs B. refused; posts
C. received; openings D. recognized; works
26. —I’ll come and see you next Sunday.
—Is that a ____? Don’t disappoint me, I hope.
A. promise B. rule C. purpose D. possibility
27. Her behavior at the wedding party was quite ____, we all felt surprised.
A. out of polite B. out of patience
C. out of place D. out of pity
28.You know I have no ___ for foreign languages.
A. present B. gift C. knowledge D. character
29. —Excuse me, how far away is it from here to the Summer Palace?
—It’s about ____.
A. half an hour drive B. half an hour’s drive C. half-an-hour-drive D. half an hours’ drives
30.To my ____, the workers set up a carved figure in front of the building.
A. pleasing B. pleasure C. please D. pleasant
31. It took ____ two hours to do their ____ .
A. Mr. Smiths;housework B. the Smith;housework
C. a Smiths;housework D. the Smiths;housework
32 I keep medicines on the top shelf, out of the children’s ____.
A. reach B. hand C. hold D. place
33.She is a ___ child, that is, she is a child ____.
A. four-years-old; four year old B. four-years-old; four years old C. four years old; four-year-old D. four-year-old; four years old
34.Lucy will be eighteen years old and her parents have a new ___ made for her.
A. dress B. trousers C. clothing D. clothes
35. Some famous characters live on the ____ from their book sales.
A. salary B. value C. bill D. income
36.The woman attending the party always wears beautiful ____.
A. clothes B. cloth C. clothing D. dress
37.There are a lot of ____ officers in this police station.
A. woman police B. women police’s
C. women police D. women’s police
38. ____ that she was ill, considering that she had been overworking for years.
A. It is no wonder B. That’s because
C. There is no doubt if D. It’s unlikely that
39.There are several _____ in this book who are different in ____.
A. character; character B. character; characters C. characters; characters D. characters; character
40.You can’t see the _____ just at the moment for they’re having an important meeting.
A. editor-in-chiefs B. editors-in-chiefs
(
解题思路
导引
) C. editors-in-chief D. editor-in-chief
理思路、巧点拨,妙解秒懂一遍过。
1.B。population后接人口数量时,前面一般与不定冠词连用,构成句型“某地+has a population of+表示数字的词”,表示“某地有多少人口”。
2.C。根据题干语境:“如果你不把课桌上所有的东西拿走,就没有足够的地方放我的文具。”room为“空间,空地”,是不可数名词,指表面位置、空间距离。place“地方”,是可数名词,指表面位置。
3.D。the doctor为Peter的同位语,这时应将’s置于同位语之后,所以应为Peter the doctor’s clinic,其余选项不符合这一要求。
4.A。word 表示“消息”时是不可数名词;loss的意思是“损失”,两词均为不可数名词。
5.B 句意为:女孩看见田鼠,就发出一阵尖叫声。“mouse”是可数名词,其复数为mice。mice是中心词,应当用field作定语。
6.C。tea 可作不可数数名词, 也可作可数名词, 前者为物质名词“茶点”;coffee作可数名词,意为“咖啡(粉末或饮料)”,也可作可数名词,意为“一份咖啡”。议题中的tea和coffee 都作可数名词,故选C。
7.D。 who(代词)+else(副词),用于主格、宾格,who else’s用于所属格,用法和yours相对应。
8.D。wealth是不可数名词,没有复数形式。work作“著作、作品”讲时,通常用其复数形式works。全句意为:“他通过印刷著名作家的作品而获得巨大财富。”
9.A。可数名词可以和不定冠词连用,而不可数名词则不可以。题中fun为不可数名词,不能与不定冠词连用。Fun为名词,应与such连用。
10.B。 within reach of somebody =within one’s reach表示“在某人的手所及之处, 在某人力量所及的范围”;反义词组为out of one’s reach/beyond one’s reach。
11.B。四个选项中只有 pleasure关为表示感情的名词,故选B。句中“to one’s +感情名词”结构,意为“使人……的是”,在句中作状语表示结果,而句中的主谓部分则是产生这种结果的原因。这种结构往往与句子结合不紧密,常放在句首,用逗号隔开。
12.B。四个选项的名词所表达的意思不同:sight视力,视野;look外貌,神态,脸色; appearance外貌。由题干中he was pleased和on his face的语境判断,只有填入B项才能与句意相符。
13.A。must 和不定冠词连用,意为“一种必不可少的事物”;necessary 是形容词,意为“必要的”;useful 意为“有用的”;important意为“重要的”,所以B,C,D均不合题意,故选A。
14.A。in a…mood意为“处于……的心境、心情”。其它选项中的mind,form , thought均不合题意,故选A。
15.B。此题考查近义名词辨析。Branches指“分部”。句意是:这家公司的总部在北京,但它的分部遍及整个国家。Companies意为“公司”,organizations“机构”,这两个名词在意义和范围上包含了head office, 所以不可选。而business(业务)在范畴上与head office不相符。
16.C。此题考查近义名词辨析。句意是:比尔正进行一些体育活动来增强自己的体力。根据句意判断,此处应该指人体的力量,所以要用strength. Ability指一个人做事的能力,force叙述人时,意指一个人的作用力和逼上梁山迫力;mind指人的心理和智力。所以这三个词与锻炼身体没有直接的联系。
17.A。句意是:对于今周末的活动,我的想法是与几个朋友外出。 idea主意,想法;opinion对某事或某物的观点、评价;mind 心理、决心;thought思想,考虑。
18.D。句意是:我相信大卫将能够找到图书室—-他有一个相当好的方向意识。have an idea of 意为“对……了解”;have a feeling of“有一种……的预感”; have an experience of“有一个……经历”; have a sense of“有一个……意识”。
19.C。在表示邀请的疑问句或希望等到对方肯定回答的疑问句中,常常用some不用any。根据答语中的I have had much(我已经喝多了)可知空格指的是不可数名词“橘汁”而不是橘子,所以C项是最佳选项。
20.C。reward报酬。本句的意思是:“提供有关抓获那个银行抢劫犯信息的将得到报酬。”Price“价格”; fund“基金”; profit“益处”。
21.D。表示两人共有的,只在后一个名词后加’s 。
22.D。injury, wound意为“创伤,刀伤”,在此不合题意;ache指局部较持续的疼痛,隐痛;pain指一般性的疼痛,也指局部的疼痛。如:I’ve got a pain here. Just here. Ouch!
23.B。此处“the sense of smell”指嗅觉,此处“the sense of touch/hearing”等表示触觉、听觉,是固定用法。其它不合题意。
24.A。因为不知道是否是我穿的“号码”、“大小”,所以才想试穿。故第一空用连词“for”表示原因,第二空用“size”表示“尺码”、“大小”。
25.C。 opening在此意为“(职务)空缺”。根据句意可以排除A项中的accept;根据搭配可以排除“refuse”,“works”。
26.A。promise意为“诺言,允诺”; rule意为“规则”;purpose意为“目的”;possibility意为“可能性”,根据题意可以排除B,C,D,故选A。
27.C。out of polite表示“出于礼貌”,out of patience表示“失去耐心”,out of pity表示“出于同情”,均不符合题意表现出来的“(她的行为)很出格;不恰当”。
28.B。“have no gift for…”意思是“没有……的天赋”;C项knowledge一般作不可数名词,另外其搭配为have a knowledge of …,“有……方面的知识”,“通晓”。
29. B。half an hour’s drive“半小时的车程”,再如ten minutes’ walk“十分钟的路程”。
30.B。四个选项中只有 pleasure关为表示感情的名词,故选B。句中“to one’s +感情名词”结构,意为“使人……的是”,在句中作状语表示结果,而句中的主谓部分则是产生这种结果的原因。这种结构往往与句子结合不紧密,常放在句首,用逗号隔开。
31.D。从信息词their我们可以知道是夫妇俩或一家人做家务,所以选the Smiths;housework是不可数名词,所以只能选D。
32.A。out of reach够不到、在……范围之外;out of hand=out of control失去控制。例如:Employee absenteeism has gotten out of hand.雇员们的旷工已经失去控制。Out of place不在适当的位置,不合适;out of hold 不是固定表达。
33.D。 数词和名词一起构成复合形容词作前置定语时,中间用连字符号连接,其中的名词要用单数。数词和名词构成的短评可以作后置定语。
34.A。dress是可数名词,可以说成a dress或dresses; trouser 常用复数,如a pair (tow pair) of trousers 一条(两条)裤子; clothing是集体名词,服装的总称; clothes“衣服”,指具体的衣服,不作单数,也不和数字连用。
35.D。C项bill(账单,清单)与题意不符,可排除;value(价值)是抽象的,不能用来消费,故B项不对;salary(工资,薪水)是按年、月发给职员的,而本句的 book sales并不是他们的工作;income意为“收入,收益”,通常指一个人收入所得,不仅限于工资。“名人出书的所得是他们工资以外的收入”,所以答案是D。
36.A。clothes“衣服”,指具体的衣服,不作单数,也不和数字连用; cloth指“衣料”; clothing是集体名词,服装的总称;dress是可数名词,可以说成a dress或dresses。
37.C。“警官”用police officer ,woman或man作定语时,如果修饰复数名词,要用women或men。
38.A。It is no wonder that……为固定句式,意为“难怪……”。例如:It’s no wonder you recognized me,we met with at the railway station yesterday. 若选C,应将There is no doubt if改为There is no doubt that。而其它选项不合题意,故选A。
39.D。character作“人物”解是可数名词,作“性格”、“品质”解是不可数名词。试题中第一空的用法是前者,第二空的用法是后者,故选D。
40.C。本题考点是名词的复数形式的构成。复合名词的复数形式一般是把复合名词中的中心(主体)名词变成复数;如果该复合名词没有中心名词,则在复合词之后加-s,将其变成复数形式。
2 / 2
学科网(北京)股份有限公司
$