argc argv[]的用法
默认分类2009-10-11 16:56:39 阅读735 评论0 字号：大中小
1. main() 参数
在Turbo C2.0启动过程中, 传递main()函数三个参数: argc, argv和env。
* argc: 整数, 为传给main()的命令行参数个数。
* argv: 字符串数组。
在DOS 3.X 版本中, argv[0] 为程序运行的全路径名; 对DOS 3.0
以下的版本, argv[0]为空串("") 。
argv[1] 为在DOS命令行中执行程序名后的第一个字符串;
argv[2] 为执行程序名后的第二个字符串;
...
argv[argc]为NULL。
*env: 安符串数组。env[] 的每一个元素都包含ENVVAR=value形式的字符
串。其中ENVVAR为环境变量如PATH或87。value 为ENVVAR的对应值如C:\DOS, C:
\TURBOC(对于PATH) 或YES(对于87)。
Turbo C2.0启动时总是把这三个参数传递给main()函数, 可以在用户程序中说明(或不说明)它们, 如果说明了部分(或全部)参数, 它们就成为main()子程序
的局部变量。
请注意: 一旦想说明这些参数, 则必须按argc, argv, env 的顺序, 如以下
的例子:
main()
main(int argc)
main(int argc, char *argv[])
main(int argc, char *argv[], char *env[])
其中第二种情况是合法的, 但不常见, 因为在程序中很少有只用argc, 而不
用argv[]的情况。
以下提供一样例程序EXAMPLE.EXE, 演示如何在main()函数中使用三个参数:
/*program name EXAMPLE.EXE*/
＃i nclude
＃i nclude
main(int argc, char *argv[], char *env[])
{
int i;
printf("These are the %d command- line arguments passed to
main:\n\n", argc);
for(i=0; i<=argc; i++)
printf("argv[%d]:%s\n", i, argv[i]);
printf("\nThe environment string(s)on this system are:\n\n");
for(i=0; env[i]!=NULL; i++)
printf(" env[%d]:%s\n", i, env[i]);
}
如果在DOS 提示符下, 按以下方式运行EXAMPLE.EXE:
C:\example first_argument "argument with blanks" 3 4 "last but
one" stop!
注意: 可以用双引号括起内含空格的参数, 如本例中的: " argument
with blanks"和"Last but one")。
结果是这样的:
The value of argc is 7
These are the 7 command-linearguments passed to main:
argv[0]:C:\TURBO\EXAMPLE.EXE
argv[1]:first_argument
argv[2]:argument with blanks
argv[3]:3
argv[4]:4
argv[5]:last but one
argv[6]:stop!
when的用法总结大全 when的用法你知道多少，今天给大家带来when的用法，希望能够帮助到大家，下面就和大家分享，来欣赏一下吧。 when的用法总结大全 when的意思 adv. 什么时候,(用于时间的表达方式之后)在那时,其时,当时conj. 在…时,既然,如果 pron. 什么时候,那时 n. 时间，时候,日期,场合 when用法 when可以用作副词 when的基本意思是“什么时候”。可用作疑问副词,用来询问某事曾发生或将要发生的时间,引导特殊疑问句; 还可用作关系副词引导限制性定语从句、非限制性定语从句和表语从句,表示“是…时候的事”。 when可用作从属连词,引导状语从句,表示时间时作“当…时,在…的时候”解; 表示条件时作“如果,要是”解; 表示对比时作“既
然,考虑到”解。当when所引导的从句的主语和主句的主语一致时,常将其主语、系动词或助动词省去,只留实义动词或表语,或者改写为短语。 when所引导的时间状语从句用一般现在时代替将来时,用现在完成时代替将来完成时。 when用作副词的用法例句 When did that happen?那件事是什么时候发生的? They stood respectfully when he entered the room.当他走进房间时，他们都恭恭敬敬地站着。 Iron will melt when it is made very hot.当铁烧得很热时就会熔化的。 when可以用作连词 when可用作从属连词,引导状语从句,表示时间时作“当…时,在…的时候”解; 表示条件时作“如果,要是”解; 表示对比时作“既然,考虑到”解。当when所引导的从句的主语和主句的主语一致时,常将其主语、系动词或助动词省去,只留实义动词或表语,或者改写为短语。 when所引导的时间状语从句用一般现在时代替将来时,用现在完成时代替将来完成时。
when 和while的用法区别 两者的区别如下： ①when是at or during the time that, 既指时间点，也可指一段时间； while是during the time that，只指一段时间，因此when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while从句中的动词必须是延续性动词。 ②when 说明从句的动作和主句的动作可以是同时，也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。 ③由when引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如： a. When the teacher came in, we were talking. 当此句改变主从句的位置时，则为： While we were talking, the teacher came in. b. They were singing while we were dancing. ④when和while 还可作并列连词。when表示“在那时”；while表示“而，却”，表对照关系。如： a. The children were running to move the bag of rice when they heard the sound of a motor bike. 孩子们正要跑过去搬开那袋米，这时他们听到了摩托车的声音。 b. He is strong while his brother is weak. 他长得很结实，而他弟弟却很瘦弱。 一。引导时间状语从句时，WHILE连接的是时间段，而WHEN连接的多是时间点 例如What does your father do while your mother is cooking? What does your mother do when you come back? 二，WHILE可以连接两个并列的句子，而WHEN不可以 例如I was trying my best to finish my work while my sister was whtching TV 三，WHEN是特殊疑问词，对时间进行提问，WHILE不是。 例如，When were you bron? 续性动词和短暂性动词 英语中的动词，是学习中的重点，又是难点。英语中的动词有多种分类法。根据其有无含义，动词可分为实义动词和助动词；根据动词所表示的是动作还是状态，可以分为行为动词和状态动词；根据动词所表示的动作能否延缓，分为延续性动词和终止性动词。 可以表示持续的行为或状态的动词，叫做“延续性动词”，也叫“持续性动词”，如：be, keep, have, like, study, live, etc. 有的表示短暂、瞬间性的动词，叫做“终止性动词”，也可叫“短暂性动词”，或“瞬间性动词”，如die, join, leave, become, return, reach, etc.
dare的用法和短语例句 【篇一】dare的用法 dare的用法1：dare用作实义动词时,有时态和人称的变化,用do, does或did来构成否定句或疑问句。 dare的用法2：dare作“敢”解时,指“勇敢”,含有大胆、鲁莽、爱冒险,或因爱慕虚荣而甘冒生命或受惩罚的危险的意味,后面通常接动词不定式,有时可省略不定式符号to。一般不用于进行体。 dare的用法3：dare还有“激某人做难办的事”的意思,即问某人敢不敢(或能不能)做某事,暗示他不敢(或不能),其后接以动词不定式充当补足语的复合宾语,不定式中的to 一般不省略。 dare的用法4：dare还可作“冒险,面对危难而不畏惧”解,直接接宾语,这是不常见的用法。 dare的用法5：dare用作情态动词,一般用于疑问句、否定句或条件句,或与hardly, never, no one, nobody等连用。有时态变化,但没有人称形式的变化,其后接动词原形。构成疑问句和否定句时不用助动词do。 dare的用法6：dare的否定式有时可用来指过去的事情。 dare的用法7：现代英语中dare的使用已趋减少,人们常用not to be afraid或not to have the courage to代替。 dare的用法8：表示“在激将法的鼓动下”用for a dare
是英式英语用法，用on a dare是美式英语用法。 【篇二】dare的常用短语 用作助动词 (aux.) how dare... I dare say you dare〔don’t you dare〕 【篇三】dare的用法例句 1. People always think I’m a fool, and I dare say they’re right. 人们总认为我是个傻瓜，想必他们是对的。 2. Don’t speak to me like that. Don’t you dare. 不要那样跟我讲话。我不允许! 3. When found, the children said they’d run away for a dare. 找到这些孩子时，他们说自己是受了激将才出走的。 4. I dare you to sit through forty-five minutes with someone like Vincent! 我想你绝不敢和文森特这样的人一起坐上45分钟! 5. I dare say he did as he was bidden. 我敢说他按照要求做了。
both, either, neither用法各不同（复习） both, either, neither这三个词都可以作代词及形容词，在考试中频频亮相，许多同学都容易将他们混淆，现将它们的用法归纳如下，让大家看个明白，轻轻松松掌握它们的词义、词性及用法。 简表说明： 补充说明： both意思是"两者都"，either意思是"两者中的任何一个"，neither意思是"两者都不"，三个词在句中都可以充当主语、宾语、定语和同位语。 ①作主语时，可单独使用，也可以与of连用，其中both接谓语动词要求用复数形式；either，neither接谓语动词一般用单数形式，但这两者在口语中作主语时，其后的谓语动词也可以用复数。例如： Both are right.= Both of the answers are right.这两个答案都对。 Either(of them)is OK. (他们两个中)任何一个都行。 ②作宾语,可单独使用，也可以与of连用，放在动词或介词之后。例如： I don't know which book is the better；I shall read both.我不知道这两本书哪一本好，所以我两本都读。 I like neither.(两个)我一个也不喜欢。 ③作定语，both后面接复数名词,either和neither后面接单数名词。例如： Both answers are right.两个答案都对。 On either side of the river there are a lot of trees.河的两边都有许多树。 Neither boy is going there.两个男孩儿都不打算去那里。 ④both作主语的同位语，一般放在实义动词前，系动词be、情态动词、助动词后；作宾语的同位语，直接放在其后(either和neither做同位语的情况较少)。例如：
when和while的用法解析、练习题及答案（附总结表格） 一、讲解三例句: 1. The girls are dancing while the boys are singing. 2. Lucy’s mother is cooking when she gets home. 3. When/While Lucy’s mother is cooking, she gets home. 二、用when或者while填空 1.______ Margo was talking on the phone, her sister walked in. 2.______ we visited the school, the children were playing games. 3.______ Sarah was at the barber’s, I was going to class. 4.______ I saw Carlos, he was wearing a green shirt. 5.______ Allen was cleaning his room, the phone rang. 6.______ Rita bought her new dog; it was wearing a little coat. 7. He was driving along ________ suddenly a woman appeared. 8. _____ Jake was waiting at the door, an old woman called to him. 9. ______ it began to rain, they were playing chess. 10. She saw a taxi coming ______ the woman was waiting under the streetlight. 三、语法 while和when都是表示同时，到底句子中是用when还是while主要看主句和 从句中所使用 的动词是短暂性动作(瞬时动词)还是持续性动作。 1、若主句表示一个短暂性动作，而从句表示的是一个持续性动作时，用 When/While。如: He fell asleep when while he was reading. 他看书时睡着了。
need和dare用法小结 最近的一次考试中出现了这么一道题： After the glasses fell to the ground and broke, the little boy his grandma about that. A. dare not tell B. dare not telling C. dare not to tell D. didn’t dare tell 答案选D。可90%的学生都选了A。这一现象引起了笔者的关注。情态动词一直都是高中英语语法中的重难点，而其中的need和dare是难点中的难点。因为这两个单词有其独特性，它们既可以作情态动词又可以用作实义动词。学生对此掌握得一直不到位。笔者根据自己多年的教学经验，现将其归纳如下： 一、need（必须、需要）的用法 1、need用作情态动词 作情态动词，need一般用于否定句、疑问句和条件句中，没有人称和数的变化，也没有时态的变化，后接动词原形。 例如：I needn’t finish my homework today. Need you go now? (请注意回答语：Yes, I must. / No, I needn’t.) *“needn’t have done”表示“本不必做而做了” You needn’t have watered the flowers, because I watered them just now. There is a lot of time left. We needn’t have taken a taxi. 2、need用作实义动词 作实义动词，need可用于任何句子中，并且有人称、数和时态的变化，后接名词、代词和动词不定式。 例如：I need a new car.
when 的用法 一、when 用作副词。 1. 用作疑问副词，引导特殊疑问句。(什么时候，何时 [at what time ])例如： ①When will you come to see me? ②When are they going to visit the Great Wall? 2. 用作连接副词，通常用来引导名词性从句[主语从句、表语从句、同位语从句、宾语从句]及起名词作用的“when ＋动词不定式”结构。(什么时候，何时 [at which; on which ])例如： ①When he comes is not known. [主语从句] ②The morning is when I am busiest. [表语从句] ④I don't know when the plane takes off. [宾语从句] ⑤I don't know when to leave for London. [宾语] 3. 用作关系副词，引导限定性定语从句和非限定性定语从句。(在…的时候 [at/on/in/during which])例如： ①Do you still remember the days when we stayed in America? ②The day will come soon when the Chinese astronauts will go to the moon. ③It happened ten years ago, when I was a child. ④We will go to the countryside at the beginning of June, when the summer harvest will start. 二 . when 用作连词。 1. 用作从属连词，意为“当……的时候[at the time when ]”，引导时间状语从句。例如： ①They learned a lot from the peasants when they stayed in the village. ②It was snowing when he arrived at the station. 【点津】如果 when 引导的从句中的主语和主句中的主语一致，且从句中的谓语动词是“be ＋分词”或从句主语是 it ，则 be 动词及其主语常可省略。例如： ③When（ he was ）asked why he was late, he made no answer. ④I'll tell him about it when（ it is ）possible. 2. 用作从属连词，意为“一……就……”，引导时间状语从句。[immediately after]例如： ①We will stand up when the teacher comes into the classroom. 老师一进教室我们就起立。 ②Fire the rockets when I give the signal. 3. 用作从属连词，意为“还没 / 刚刚/刚一……就”，引导时间状语从句。[immediately after]例如： ①I had hardly opened the door when he came in. 我刚一开门，他就进来了。 ②I had not been reading for half an hour when I heard someone call my name. 【点津】hardly…when和no sooner…than的结构要注意三点：意思为“一A就B“；A句通常用完成时态；hardly 和 no sooner 位于句首时要注意部分倒装。 4. 用作从属连词，意为“倘若，如果”，表示条件。例如： ①Turn off the switch when anything goes wrong with the machine. 如果机器发生故障，就把电源关上。 ②He will be likely to recover when he is operated on. 5. 用作从属连词，意为“既然，尽管”，表示让步。例如： ①Why use metal when you can use plastic?既然能用塑料,为什么用金属? ②They kept trying when they knew it was hopeless. 尽管他们知道那件事没有希望，可是他们还在不断地努力。6. 用作并列连词，意为“在那时，届时;就在这时”，表示时间。这时主句中可以用过去进行时，过去完成时或“ was/were about to do sth. ”结构。 ①Last night I was about to go to bed when the phone rang. ②I was cooking in the kitchen when someone knocked at the door. ③He had just finished the book when supper was served. 7. 用作并列连词，意为“虽然、然而、可是”，表示转折。例如： ①He usually walks to work when he might take a bus. 虽然他可 以坐公共汽车上班，但他却常常步行上班。 ②I had only twenty dollars when I needed thirty to buy the dictionary.我需要 30 美元买那本字典，可是我只有20美元。 8. 用作并列连词，意为“而、却”，表示对比。例如： How can he say that everything is fine when it's obvious that it is not? 他怎能说一切都好呢？情况显然不是那样。 三 . when 用作代词[which time]。 when 作为代词常常位于介词之后，意为“那时，什么时候”。例如： ①Since when have you been studying Japanese? 【点津】since when 作引导词时是“介词（since）+关系代词（when）”的结构，when意为which time。since when常引导非限制性定语从句，从句应用完成时态。 ②I came here in 1949, since when I have been engaged in this work. 我1949年到这里，从那时起我就担任这项工作。 ③We came back on Tuesday, since when we have been working in the repair shop. ④We came a week ago, since when the weather has been bad. 四、when 还可用作名词，前面常常用定冠词 the。 the when 表示事 件发生的时间,常常与 the where, the how 并列使用。 He told the police the when and the how of the accident. 他告 诉警察事故发生的时间及发生的原委。 ［巩固练习］ 1. I remember ______ this used to be a quiet village. A. when B. how C. where D. what 2. Why do you want a new job _____ you've got such a good one already? A. that B. where C. which D. when 3. It was an exciting moment for these football fans this year, ______ for the first time in years their team won the World Cup. A. that B. while C. which D. when 4. We are living in an age _______ many things are done on computer. A. which B. that C. where D. when 5. The reporter said that the UFO ______ east to west when he saw it. A. was travelling B. travelled C. had been travelling D. was to travel 6. ______ got into the room _________ the telephone rang. A. He hardly had; then B. Hardly had he; when C. He had not; than D. Not had he; when 7. ---- Can I join your club, Dad? ---- You can when you _______ a bit older. A. get B. will got C. are getting D. will have got 8. I shall never forget those days ________ I lived in the countryside with the farmers, ________ had a great effect on my life. A. that; which B. when; which C. which; that D. when; who 9. The film brought the hours back to me ______ I was taken good care of in that faraway village. A. until B. that C. when D. where 10. He was about to tell me the secret ______ someone patted him on the shoulder.
WHEN与WHILE用法区别 when, while这三个词都有"当……时候"之意，但用法有所不同，使用时要特别注意。 ①when意为"在……时刻或时期"，它可兼指"时间点"与"时间段"，所引导的从句的动词既可以是终止性动词，也可是持续性动词。如： When I got home, he was having supper.我到家时，他正在吃饭。 When I was young, I liked dancing.我年轻时喜欢跳舞。 ②while只指"时间段"，不指"时间点"，从句的动词只限于持续性动词。如：While I slept, a thief broke in.在我睡觉时,盗贼闯了进来。 辨析 ①when从句与主句动作先后发生时，不能与while互换。如： When he has finished his work, he takes a short rest.每当他做完工作后，总要稍稍休息一下。(when = after) When I got to the cinema, the film had already begun.当我到电影院时，电影已经开始了。(when=before) ②when从句动词为终止性动词时，不能由while替换。如： When he came yesterday, we were playing basketball.昨天他来时，我们正在打篮球。 ③当从句的谓语是表动作的延续性动词时，when, while才有可能互相替代。如：While / When we were still laughing, the teacher came in.正当我们仍在大声嬉笑时，老师进来了。 ④当从句的谓语动词是终止性动词，而且主句的谓语动词也是终止性动词 时,when可和as通用，而且用as比用when在时间上更为紧凑，有"正当这时"的含义。如： He came just as (or when) I reached the door.我刚到门那儿，他就来了。 ⑤从句的谓语动词如表示状态时，通常用while。如： We must strike while the iron is hot.我们应该趁热打铁。 ⑥while和when都可以用作并列连词。
dare过去式和用法例句 dare的过去式和其他时态： 过去式: dared 过去分词: dared 现在分词: daring dare的用法： dare的用法1：dare用作实义动词时,有时态和人称的变化,用do, does或did来构成否定句或疑问句。 dare的用法2：dare作“敢”解时,指“勇敢”,含有大胆、鲁莽、爱冒险,或因爱慕虚荣而甘冒生命或受惩罚的危险的意味,后面通常接动词不定式,有时可省略不定式符号to。一般不用于进行体。 dare的用法3：dare还有“激某人做难办的事”的意思,即问某人敢不敢(或能不能)做某事,暗示他不敢(或不能),其后接以动词不定式充当补足语的复合宾语,不定式中的to一般不省略。 dare的用法4：dare还可作“冒险,面对危难而不畏惧”解,直接接宾语,这是不常见的用法。 dare的过去式例句： 1. he has also dared to take unpopular, but principled stands at times. 他有时也会大胆坚持不受欢迎、但却有原则性的立场。
2. no one dared shoot for fear of hitting pete. 没人敢开枪，怕伤着皮特。 3. he followed her, incensed that she'd dared to leave him alone. 他跟着她，对她竟敢对自己置之不理感到极其愤怒。 4. she said it as loudly as she dared. 她壮着胆子大声说了出来。 5. i wouldn't have dared to defy my teachers. 我可不敢不听老师的话。 6. the neighbours all stood aghast, and dared not move. 邻居们都目瞪口呆, 再不敢动. 7. unafraid of attack , they dared ( to ) run such risks. 他们不怕围攻, 敢于承担这样的风险. 8. he dared not show that he was pleased. 他不敢表示自己觉得高兴. 9. she dared the danger of bankruptcy. 她敢冒破产的风险. 10. i dared him, but he didn't. 我向他挑战, 可是他不敢应战. 11. how dared you to play truant! 你竟敢逃学. 12. how dared they do such a thing? 他们怎么敢做出这样的事? 13. he dared me to jump over the stream.
一、作为副词，它有以下的用法： 1. 作为疑问副词，引导特殊疑问句，意为“什么时候；何时”。 （1 ）When will they come back？ （2 ）What time will they come back？ 回答when 引导的从句，不一定指出具体的时间点。如回答句（ 1 ）可用tomorrow，next month 等。而回答what time 引导的问句，则必须说出具全的时间点，如at two o'clock，at five past ten 等。 2. 作连接副词，引导名词性从句或不定式，意为“什么时候”。从句使用陈述句语序，时态根据实际情况而定。 （1 ）I'd like to know when they will come. 我想知道他们什么时候来。（when 引导宾语从句） （2 ）Can you tell me when the bank opens？你能告诉我银行什么时候开门吗？（when 引导宾语从句） （3 ）When she'll be back depends much on the weather. 她何时回来在很大程度上取决于天气。（when 引导主语从句） （4 ）Have you decided when to go sightseeing？你们已经决定什么时候去郊游了吗？（when 引导不定式结构） 3. 作疑问代词，常和介词since，till，up to 等连用，意为“什么时候”。 如：（1 ）Since when have they had the house？他们从什么时候起有这幢房子的？（2 ）Till when is the library open？图书馆开放到几点呢？ 4. 作关系副词，引导限制性定语从句和非限制性定语从句。 （1 ）The days are gone forever when the Chinese people were looked down upon. 中国人民被人轻视的日子一去不复返了。 （2 ）The main school holidays are from mid-December till early February，when the days are long and warm. 学校的主要假期是从12 月中旬到2 月初，这段时间里白天长而且很温暖。 （3 ）Considering （the time）when these paintings were done，they are in excellent condition. 考虑到这些油画的创作时期，它们保存的状况是极好的。 （4 ）Do you remember （the time）when the three of us went on a picnic？你还记得我们三个人去野餐的那段时光吗？ A. 在定语从句中，that 在某些条件下可用来代替when ，这时其先行词通常是time，
Dare的用法练习 知识点整理 （1）作情态动词 ·用于疑问句、否定句、条件句 ·有过去式变化 ·后接动词原形 ·否定式直接加not ·疑问句之间提前 （2）作实义动词 ·有人称和数量的变化 ·肯定句中要跟带to的不定式 ·否定句、疑问句中to可带可不带 ·to为不定式符号 附录：情态动词与实义动词的区别 ·情态动词只表示对某事的期待、要求、推测 ·情态动词不表示某事的发生状态 ·情态动词没有人称、数的变化 ·情态动词没有非谓语形式，即没有不定式、分次等形式。 一般来说，在疑问句与否定句中，使用情态动词的dare。 Dare he say "no"? He dare not/daren't say "no". 一、练习 （一）翻译句子 （1）他敢告诉我们真相吗？(一般现在时) （2）他不敢告诉我们他知道些什么。（一般过去式） （3）恐怕你不敢做这样的事。 （4）如果你敢违反规定，就会受到处罚的。 （5）我想他敢告诉经理事实的真相。 （6）这个学生不敢在课堂上提出任何问题。 （7）你敢在这么拥挤的车道上开车吗？
参考答案 （1）Dare he tell us the trurh? Does he dare (to) tell us the truth? （2）He dared not tell us what he knew. He did not dare (to) tell us what he knew. （3）I’m afraid you dare not/daren’t do things like this. I’m afraid you do not dare (to) do things like this. （4）If you dare to break the rule, you will be punished. If you dare break the rule, you will be punished. （5）I suppose he dares to tell manager the truth. （6）This student doesn’t dare (to) ask any question on class. （7）Do you dare (to) drive on such a crowded road?
一、all的句法功能 all “三者或三者以上都”。具有名词和形容词的性质，在句中都可作主语、宾语、表语、定语和同位语。既能修饰可数名词又能修饰不可数名词。代替不可数名词作主语时，谓语动词用单数形式，代替复数可数名词时，谓语动词用复数。 1．作主语 All enjoyed themselves.（可数）所有的人都玩的很开心。 Now all was changed.（不可数）现在一切都改变了。 2. 作宾语 I love all.我都喜欢 3．作表语 Is that all you want to say? 你要说的就是这么一些？ 二、both的用法 1.Both 可作形容词、代词或副词用，意思是“两个”、“双方”、“两个都”。在句中可作主语、宾语或同位语。只能修饰复数的可数名词。作主语时谓语动词用复数形式。 如：Both are right. 两者都对。(主语) I like both. 两个我都喜欢。(宾语) 2. Both可参与构成名词词组，也可和动词连用，还可与and构成并列连词。在使用时，要注意下列几点：
（1）both和all和be动词、助动词、情态动词连用时，放在它们得 后面。 They are both students. 他们都是学生。 They are both working hard. 他们两人都努力工作。 You can all go home. 你们都可以回家了。 （2）和实义动词连用时放在实义动词之前。如：They both ran away. 他们两人都跑走了。 My brother and my sister both ran to help me. 我弟弟和我妹妹都 跑来帮助我。 They both like swimming . （3）both和all跟“of 短语”连用时，后接名词时both和all后面 可以省略of； All (of) the students are ready for class. 所有的学生 都做好了上课准备。 Both her children go to the same school. 她的两个孩子在同一 个学校读书。 Both men were interested in the job. 两个人都对这项工作感兴趣。 Both his eyes were severely burned. 他的双眼都严重烧伤 了。 Why not buy both? 为什么不把两件都买下?
When + doing"的用法 Every teacher should, therefore, follow in his footsteps and emphasize benevolence when teaching. 因此，每个老师教学时，应效法孔子并强调仁的道理。 = Every teacher should,therefore,follow in his footsteps and emphasize benevolence when he teaches . 在以when,while,if, once ,though,unless 等六个连词引导的状语从句中，若主语与主句的主语相同时，可将从句中的主语删除，并将之后的动词变成现在分词。若是be动词，一律变成分词being,而being再予以省略。 1. when you do the work, you should be careful. = When doing the work, you should be careful. 2. If I am free, I'll do it. = If free, I'll do it. 3. when you do the work, you must be careful. = When doing the work, you must be careful. 4. Though he is poor, he is happy. = Though poor, he is happy. 5. While I was watching Tv, I fell asleep. = While watching TV. I fell asleep. 6. When you drive a car, you should be alert. = When driving a car, you should be alert.
as when while 的区别和用法 as when while的用法 一、as的意思是“正当……时候”,它既可表示一个具体的时间点，也可以表示一段时间。as可表示主句和从句的动作同时发生或同时持续，即“点点重合”“线线重合”；又可表示一个动作发生在另一个动作的持续过程中，即“点线重合”， 但不能表示两个动作一前一后发生。如果主句和从句的谓语动词都表示持续性的动作，二者均可用进行时，也可以一个用进行时，一个用一般时或者都用一般时。 1、As I got on the bus，he got off. 我上车，他下车。（点点重合）两个动作都是非延续性的 2、He was writing as I was reading. 我看书时，他在写字。（线线重合）两个动作都是延续性的 3、The students were talking as the teacher came in. 老师进来时，学生们正在讲话。（点线重合）前一个动作是延续性的，而后一个动作时非延续性的 二、while的意思是“在……同时（at the same time that )”“在……期间(for as long as, during the time that）”。从while的本身词义来看，它只能表示一段时间，不能表示具体的时间点。在时间上可以是“线线重合”或“点线重合”，但不能表示“点点重合”。例如： 1、He was watching TV while she was cooking. 她做饭时，他在看电视。（线线重合） 2、He was waiting for me while I was working. 我工作的时候，他正等着我。（线线重合） 3、He asked me a question while I was speaking. 我在讲话时，他问了我一个问题。（点线重合）
dare用法 用作情态动词时:dare/dare not do sth. 用作实意动词：don't dare to do sth I dare not ask him this question. I don't dare to ask him this question. 我不敢问他这个问题。 dare的用法 1）dare用作实义动词，此时其后的动词不定式可带to也可不带to，且dare有人称和数以及时态的变化。例如： I dare to jump down from the top of the wall.我敢从那墙头上跳下来。 She doesn\'t dare(to)meet her teacher\'s eyes.她不敢与老师对视。 2）dare用作情态动词，后跟动词原形，主要用于疑问句、否定句和条件句中。例如： How dare she do things like that to me?她怎么敢对我做那种事? -Dare you catch the mouse?你敢去抓那只老鼠吗？ -I daren\'t do that.我不敢抓。 If you dare say that to our teacher,I would vote for you.如果你敢向我们的老师说那件事，我就投你一票。 dare v.（动词）
dared，dar.ing，dares v.t（及物动词） To have the courage required for: 敢：有要求达到的胆量： The gymnast dared a breathtakingly difficult move. 这位体操选手敢于做惊险的高难度动作 To challenge(someone)to do something requiring boldness: 挑衅：挑起（某人）去做要求勇敢的事： They dared me to dive off the high board. 他们挑衅我从高台上跳下水中 To confront or oppose boldly;defy.See Synonyms at defy 向…挑战：勇敢地面对或反对；公然反抗参见defy v.intr.（不及物动词） To be courageous or bold enough to do or try something: 勇于，胆敢：有足够的勇气或胆量做或试着做某事： Go ahead and dive if you dare. 如果你敢，尽管跳下水去 v.aux.（助动词） To be courageous or bold enough to: 胆敢：有足够的勇气和胆量： I dare not say.How dare she go? 我不敢说。她怎么敢去呢? n.（名词） An act of daring;a challenge. 挑衅的行为，挑战 Depending on its sense,the verb dare sometimes behaves like an auxiliary verb(such as can or may)and sometimes like a main verb(such as want or try).When used as an auxiliary verb,dare does not agree with its subject: