enough在句中的用法、That/This/It is why...等重点句型详解

enough在句中的用法、That/This/It is why...等重点句型详解知识点包括enough在句中的用法、That/This/It is why...、现在分词作状语、try在句中的用法、as为从属连词的用法、不定式作目的状语的用法、since的用法、部分倒装等部分，有关enough在句中的用法、That/This/It is why...等重点句型详解的详情如下：

enough在句中的用法

To our left，snow­covered mountains disappear into clouds that seem almost close enough to touch.

在我们的左边，白雪覆盖的群山消失在似乎近在咫尺、触手可及的云层中。

(1)句式分析：这是一个主从复合句。主句是snow­covered mountains disappear into clouds，that seem almost close enough to touch是that引导的定语从句，修饰先行词clouds，that在定语从句中作主语。

(2)enough 可以用做形容词、副词或代词：

①作副词(句中的用法)。用于修饰形容词或其他副词，多置于被修饰词之后，其后常接 for 短语，to do 短语，以及 for sb. to do...结构。修饰动词时也常放在动词之后。如：

The boy is old enough to go to school.

这个男孩到上学的年龄了。

She couldn't run quickly enough to catch up with him.

她跑得不够快，追不上他。

The meat is not cooked enough.

肉炖得不够熟。

②作形容词。用于修饰名词，置于名词前，但修饰 time时，放在time 前后均可。如：

I have enough time to do the work.

＝I have time enough to do the work.

我有足够的时间做此项工作。

③作代词。可作主语和宾语。如：

I have had enough. Thank you.

我吃得已经够多的了，谢谢。

hat/This/It is why...

This is why we’re here—to observe Tibetan antelopes.

这就是我们来这里的原因——观察藏羚羊。

(1)句式分析：句中包含了why引导的表语从句。

(2)That/This/It is why...表示“那/这就是为什么……”，why引导表语从句。

That was why they refused to sign the agreement.

那就是他们为什么拒绝签订协议。

The deadline is near. This is why we are very busy.

最后期限要到了，这就是为什么我们很忙。

[思维拓展]

It/This/That is because...这/那就是因为……

The reason why...is/was that...……的原因是……

He has heart disease. That is because he has been smoking too much.

他有心脏病，那是因为他抽烟太多了。

现在分词作状语

Watching them move slowly across the green grass，I'm struck by their beauty.

看着它们慢慢地穿过绿色的草地，我被它们的美丽所打动。

(1)句式分析：本句中Watching them move slowly across the green grass是现在分词短语作时间状语，相当于When I am watching them...。

(2)现在分词作状语用法浅析：

He walked down the hill, singing softly to himself.

他从山上走下来，一路哼着小曲儿。(伴随状语)

He dropped the glass, breaking it into pieces.

他把玻璃杯弄掉了，结果杯子摔得粉碎。(结果状语)

He came running into the room.

他跑进屋来。(方式状语)

Having been held back by the traffic jam, she couldn't get there on time.

她因交通阻塞而被耽误，无法准时到达那里。(原因状语)

Having finished his homework, he went out to play football.

完成作业后，他出去踢足球了。(时间状语)

try在句中的用法

“We're not trying to save the animals，”he says.“Actually，we're trying to save ourselves.”

“我们不是在试图拯救动物，”他说。“事实上，我们是在拯救自己。

句式分析：句中try to do sth.意为“设法做某事”。

I tried to persuade her to go with me，but failed.

我设法劝她和我一起去，但没成功。

[思维拓展]

try doing sth.尝试做某事

Try writing a poem on your own.

试着独自写首诗。

as为从属连词的用法

Their habitats were becoming smaller as new roads and railways were built.

随着新的公路和铁路的修建，它们的栖息地变得越来越小。

(1)句式分析：这是一个主从复合句。主句是Their habitats were becoming smaller，as new roads and railways were built是as引导的时间状语从句。

(2)句中as为从属连词，意为“随着”。

It's becoming warmer and warmer as the spring draws near.

随着春天的临近，天气越来越暖和。

不定式作目的状语的用法

Zhaxi and other volunteers watched over the antelopes day and night to keep them safe from attacks.

扎西和其他志愿者日夜守护着这些羚羊，以确保它们不被猎食。

(1)句式分析：本句是简单句。to keep them safe from attacks是不定式短语作目的状语。

(2)不定式作目的状语的用法：

①不定式作目的状语多表示将来的动作，因此只有to do sth. 和 to be done 的形式，不能用完成式或进行式。如：

He tried to be a good child to be liked by his parents.

为了被父母喜欢，他努力做一个好孩子。

②有时为表示强调，可在不定式前加上in order/so as, 但是so as to do 不可位于句首。如：

为了拿到奖学金，她刻苦学习。

→(In order)To win the scholarship, she studies hard.

→She studies hard(so as) to win the scholarship.

③当不定式有自己的动作执行者时，也就是说当不定式的逻辑主语与句子的主语不一致时，要用不定式的复合结构，即在不定式前加“for＋名词或宾格代词”。如：

He opened the door for the children to come in.

他打开门让孩子们进来。

since的用法

 The government，however，does not intend to stop the protection programmes，since the threats to the Tibetan antelope have not yet disappeared.

然而，政府并没有打算停止这些保护项目，因为对藏羚羊的威胁依然存在。

(1)句式分析：这是一个主从复合句。主句是The government，however，does not intend to stop the protection programmes，后面是since引导的原因状语从句。

(2)since的用法：

①conj.意为“因为，既然”。

Since you are unable to answer，perhaps I should ask someone else.

既然你回答不了，也许我该问别人。

②conj.(常与现在或过去完成时连用)意为“自……以来；从……以后”。

It had been a year since Susan became blind.

苏珊失明已经一年了。

③prep.(常与现在或过去完成时连用)意为“自……以来；从……以后”。

I have not heard from him since last year.

自从去年以来我一直没有收到过他的信。

④adv.(常与现在或过去完成时连用)意为“从那时以后；后来”。

I have not seen him since.

从那以后，我就没见过他。

部分倒装

Only when we learn to exist in harmony with nature can we stop being a threat to wildlife and to our planet.

只有学会和大自然和谐共处，我们才不会成为野生生物和地球的威胁。

(1)句式分析：本句是倒装句。正常语序是：We can stop being a threat to wildlife and to our planet only when we learn to exist in harmony with nature。

(2)“only＋状语(从句)”位于句首时，句子(或主句)要部分倒装。如：

Only in this way can you make improvement.

只有用这种方法你才能有所提高。

Only when I reached the top of the mountain did I feel a great sense of achievement.

只有当我到达山顶时，我才有极大的成就感。

[思维拓展]

部分倒装的常见情况：

(1)nor，neither，never，seldom，little，by no means，rarely，scarcely，in no way等表示否定或半否定的词(组)位于句首时，句子部分倒装。

(2)not until、“only＋状语(从句)”位于句首时，句子(或主句)部分倒装。

(3)so/such...that...句型中，so/such置于句首时，主句部分倒装。

(4)no sooner...than...，hardly/scarcely...when...中，no sooner，hardly/scarcely位于句首时，主句部分倒装。

(5)not only...but also...连接并列分句，且not only位于句首时，not only所在的分句部分倒装。

(6)as/though引导的让步状语从句，形容词、名词、动词提前构成部分倒装。

(7)虚拟条件句中，条件从句中的if省略，而把were，had，should等提前，构成部分倒装。

Never shall I do this again.

我再也不会做这种事情了。

Hardly had he arrived when it began to snow.

他刚到，天就下起雪来了。

Tired as he was，he stayed up late.

虽然很疲倦，可他很晚才睡。

[巧学妙记]

口诀巧记部分倒装：

only修饰副介状，位于句首半倒装；

否定意义副连词，位于句首须倒装；

so和such置句首，主句主谓要倒装；

not only开头句，所在分句须倒装；

had，were，should置句首，条件从句半倒装。