Students with enough knowledge and skills will be admitted. People who don't have their ID cards cannot get in. People without their ID cards cannot get in.
④ 从句谓语动词是wish, desire , want , hope 等可用于这一缩略结构， 但从句谓语动词是like则不行。（？因为liking表示“喜爱”） people who wish / wished to go on the tour 缩简成：people wishing to go on the tour fans who hope/ hoped for a glimpse of the star 缩简成：fans hoping for a glimpse of the star （见百度百科：形容词从句） 22 . 插入语作独立成分
在句子中或末尾插入单词、短语、分句等， 用于调节说话人的口气的成分称为插入语， 起评注作用。插入语可用逗号或破折号与句子主要成分分开， 有时也可以不用标点。 1） 分句用作插入语。 He is, I hear, a great scholar. The girl is, I think, the most intelligent actress in the troupe. His suggestions, I'm afraid, are not well-founded. 可用作插入语的分句有:I admit, I believe, I expect, I find, I guess, I hear, I hope，I'm afraid, I'm sorry to say, I imagine, I remember, I suppose, I think 等。 2) 状语分句用作插入语 This is, as far as I know, not what he really wants. You can, if you like, take it home. The difference, as I see it, is one of method and not of principle. 可用作插人语的状语分句还有:as you know, as I told you, as it turned out等。 有时可用其省略形式作插人语:if ever如果有的话if possible如果可能的话 if any如果真有的话if so若是这样if not若不（这样） The island is seldom, if ever, There are few, if any, visited by ships.这个岛难得有船停靠。 mistakes in the book.这本书里即使真有错误，也不多。 3）由what 构成的两类短语作惯用插入语， 其结构如下。 ① “what + be ＋ 比较级形容词” 含义为 ”而且， 尤有甚者” Tom participated and, what is more surprising, He said nothing and, what is worse, He is handsome,clever, and what is better still won the prize. laughed at us. very diligent. ②“what we call/consider; what is called/considered”含义为“所谓的/认为的”
This is what we call human touch or human nature. 这就是我们所说的人情味或人性。 We should improve what is called the quality of living. 我们应该提高所谓的生活品质。 That is what we consider an ideal size for a small space garden. 这是我们认为理想中的小空间花园的大小。
This is what is considered the lightweight construction. 这就是所谓的轻型建筑。
Scientists have discovered the bones of what is thought to be the oldest human species in a cave in South Africa. 科学家在南非的一处岩洞里发现了被认为是最早人类的骨骼。
These colours are caused by what is known as the interference of light.
这些颜色是由已知的光的干涉产生的。
If the economy is “doing well”, then the prices of stocks tend to rise in what is referred to as a “bull market”. 如果国民经济发展得好，那么股价就会在所谓的“牛市”里上升。
At that time Mexico and what is now southwestern U. S. were all Spanish territory. 那时，整个墨西哥和现在美国西南部的地方都是西班牙属地。 4) 由不定式构成的插入语 To be frank, To make the matter worse, To tell you the truth, To be honest, 5）插入语用于特殊疑问句中，其结构如下：
特殊疑问词+{ do you think, do you suppose; do you believe, can you guess; did you say, did you suggest} + 主语 + 谓语 When Where What Who How fast do you think do you suppose did you suggest do you guess did you say he will come? 你认为他什么时候会来？ they have gone? 你认为他们到哪儿去了？ he should read? 你建议他该读点什么？ that woman is? 你猜那女人是谁？ he drove? 你说他车开得有多快？ I’m not that interested in the Olympics. I locked my key in the car. American fast food makes me sick. she was more of a hindrance(妨碍者) than a help. 说实在的，她没帮上忙，反而成了累赘。 （三）状语从句
状语从句是副词性从句，在句子中起状语作用，用于修饰主句中的动词、形容词或副词等。状语从句放在主句之前时，常用逗号分开; 放在主句之后，一般不用逗号。状语从句按其意义和作用可分为时间、原因、地点、条件、让步、目的、结果、方式、比较等9种。
名称 ：： 常用连词 1. 时间状语从句 ： when, while, as, before, after; till/until, since, by the time, once, as soon as, hardly ... when, no sooner ... than, the first time, the moment, etc. 2. 原因状语从句 ： because, since(既然；由于)，as, for; seeing that(鉴于)，considering that (考虑到),now that(既然)，in that(因为),not ... because(不是因为)，not that ... but that, etc. 3. 地点状语从句 ： where(在?的地方)，wherever(在任何?的地方)， anywhere(任何地方)，everywhere(到处)，etc.
4. 条件状语从句 ： if, unless, on condition that, provided (that), as long as, as far as, suppose/supposing (that) , what if (如果?将会怎样)，in case (如果，万一)，given that (考虑到；倘若)，when(如果，只要)，where(如果，只要)， while(只要)
5. 让步状语从句 ： (al) though (虽然)，while (而，虽然)，if (即使),granted ( that)(即使)， even though/even if(即使)，whether ... or,疑问词 + ever 或 no matter + wh-疑问词，nevertheless, etc. 6. 目的状语从句 : in order that(为了)，so that (为的是，以便)，for fear that (生怕，唯恐)， lest(以免)，in case(以防),etc.
7. 结果状语从句 : so that(所以)，so ... that, such that，such ... that, but (that/what)(而 不)，as a result, therefore, consequently, etc.
8. 方式状语从句 : (just) as, (in) the way (that) , as if, as though, etc. 9. 比较状语从句 : than,“the +比较级?the +比较级”,“as +句子,so +句子”(正如...一样，?也同样)，“ A is to B what C is to D”，while, whereas, however, nevertheless, etc.
1. 时间状语从句
时间状语从句表示主句动作发生的时间，由下列引导词引导: when, while, as； before, after； until, since, by the time； once, as soon as； no sooner ... than, hardly ... when； the moment 等
1) when“在?的时候”；while“在?期间”;as“正当?的时候” when与when连用的动词可以是表时段的持续性动词，也可以是表时间点 的瞬间动词，强调特定时间。具体用法如下：
when的用法
① 主句和从句同时用现在或过去时：表示在特定时间里两个动作同时发生（同时性），（a） 或两个动作相继发生。（b-c）
a) She blushes when you praise her.
b) When he got on the bus, he came to the back near where I was sitting. c) When the lights went out, I lit some candles. ② 主句用将来时态，从句用一般现在时表将来。（主将从现）
When he arrives, he will tell us about the truth. When he comes again, I'll show him the photo.
③ 主句用将来时，从句用现在完成时：强调从句的动作先于主句发生（先时性）。
When I have finished, I will tell you.
When I have found out the secret in the magic, there won't be any more excitement.
④ 主句用一般过去时，从句用过去进行时，表示从句动作进行过程中主句动作发生了，这时常可用while/just as替换。
When I was getting off the car, it started to rain. The phone rang when we were having lunch.
When/While/Just as I was having dinner at a restaurant, I saw Tony coming in.
⑤ 主句用进行时置于句首，从句用一般式，强调从句动作的突然性，when意为“忽然”。
He was just running downstairs when he saw me.
The astronaut was taking photos of the earth when he noticed a new star.
⑥ 主句用过去完成时置于句首，从句用一般过去时：主句用否定意为“还没?就”；主句用肯定意为“刚?就”。
I hadn't been reading for half an hour when I heard steps outside. I had been there little more than a week when I set to work in earnest. ⑦ when的含义为“在?的情况下”。在句子中有时可以翻译为“although”( a)， “since”(b) 或“if”(c) 。
a) She refuses help when she has many friends. b) Why do you walk when you have a car?
c) How can I help him to understand when he won't listen to me. ⑧ when后接情态动词的完成式（虚拟结构），含义为“本可以，本应该?”。
He stopped trying when he might have succeeded.
She was playing in the yard when she should have been working.
while：与while连用的只能是持续性动词，表示与主句行为的同时性，强调动作过程。while还可用以对比，when则不能。用法如下：
while的用法
① 表示现在情况，从句常用一般现在时或现在进行时。
We must strike while the iron is hot.
Work while you work, play while you play. You must be very careful while you are driving.
② 主句和从句都用过去时或过去进行时，强调两个动作同时发生。
I went shopping while Linda cleaned the house. What were you doing while he was taking a walk? While she was cooking, he was digging in the yard. ③ 有时有对比的含义，意为“然而，但是”。表示对照，说明前后两种情况完全相反。
Tom is outgoing while Jane is shy and quiet. Some waste food while others haven't enough. I was having a lecture while he was playing.
说明：while还可以引导让步状语从句或条件状语从句。
as:用于强调同一时间里两件事情先后发生或产生变化，意为“正当”，有时有随着?”的含义。具体用法如下： as的用法 ① 表示从句动作一发生，主句动作接着发生。
As I got closer, I found the cage was a trap. As the sun rose, the fog disappeared. ② 表示从句与主句的两个动作同时发生。
He trembled as he spoke.
As she sang, the tears rang down her cheeks.
③ as从句用进行时态时常与just连用，构成短语“just as”。
Just as he was speaking, a policeman showed up. He arrived just as I was leaving.
2) before“在?之前”，after“在?之后”强调事件的先后关系
before:表示两件事的先后关系。由于before含义为“在做某事之前（指此事 尚未做）”，本身有否定含义，因此，before后永远不能出现no, not, never, hardly, little等否定或半否定词。具体用法如下： before的用法 ① 表示主句动作发生在before引导的从句动作前（无论现在、过去或将来），意为“在?之前”。
All things are difficult before they are easy. I started my meal before he arrived. Before I leave, I must phone my parents.
② 若从句为过去时，主句可用过去完成或一般过去时。有时可以在before前加表时间的词语，意为“在（多久）之前”。
I had waited an hour before he showed up.
He had finished his homework before you came.
They reached the station twenty minutes before the train finally arrived.
③ 有时，before引导的从句用过去完成时仍表示主句动作先发生，含义为“不等?就”。
He arrived before I had finished my lunch. 我还没吃完午饭，他就到了。
I left university before I'd taken the final exams. 我没有参加期末考就大学辍学了。，. ④ 由before构成的句型1: “sb. +过去完成否定式+时间词语+ before”，意为“刚?没多久就?”。before/when通用。
I hadn't waited long before he came. 我刚等候不久他就来了。
They hadn't been married a month before they quarrelled. 他们刚结婚不到一个月就吵架了。
⑤ 由before构成的句型2: “It + be not long before”，意为 “（不久）?就”，强调时间短。
It wasn't Iong before he told me everything about it. 不久他就把一切都向我说了。 It wont be Iong before he comes. 他马上就会到。
⑥ 由before构成的句型3: “It + be +表时间的词语+ before”意为“?（之后）才”，强调某事要多久以后才会发生。
It will be ten years before we meet again. 要 10年后我们才能再见面。
It was evening before we reached that little town. 傍晚时分我们才到达那个小镇。
after:指一件事情发生后另一件事情接着发生，表示主句和从句两个动作的 先后关系。 after的用法 ① 指某事发生后另一事接着发生，主句和从句可以都用过去式强调动作联系紧密(a-b)。 从句用过去完成时，强调事件发生的因果关系(c-d)。
a) After she finished her work, she hurried to the nursery to pick up her child. b) What happened after he got married.
c) I found your coat after you had left the house. d) He felt better after he had taken the medicine. ② after之前常可以加上表示时间长度的词语，说明两件事情相隔有多久。
I found the letter long after he had gone away. I visited her shortly after she returned home.
Three days after he was released from hospital he went to work again.
3）till/until“直到”，since “自从”，by the time“不迟于” till与until:意为“直
到”，常可换用，但till不能置于句首。 till/until的用法
① 主句为肯定句：谓语动词为表持续的动词，如be, live, last, stand, stay, wait, work 等时，表示主句的动作延续到从 句所表达的动作发生为止，意为“一直到?时（为止）”。
He cleaned his shoes until they shone.
She stood there until he had passed out of sight.
In British law the accused is presumed to be innocent until he is proved to be guilty. 在英国的法律中，被告在其罪状被证实之前被推定为无罪。
② 主句为否定句：谓语动词只能用非持续动词，如come, stop, leave等，until表达的是主句动作的起点，意为“直到? 才，在?之前（不）”。
He did not get up till his mother came in.