Without air, we should be forced to seek shelter from the sun...

5特殊的虚拟语气词：should

1） It is demanded / necessary / a pity + that…结构中的主语从句的谓语动词要用should 加动词原形， should 可省略。

句型：

(1)suggested

It is (2)important that…+ (should) do

(3) a pity

(1)suggested, ordered, proposed, required, demanded, requested, insisted； + (should) do

(2)important, necessary, natural, strange

a pity, a shame, no wonder

(3)It is suggested that we (should) hold a meeting next week

It is necessary that he (should) come to our meeting tomorrow

a 同现在事实相反的假设。

句型 ： 条件从句 主句

一般过去时 should( would) +动词原形

If they were here, they would help you

b 表示于过去事实相反的假设。

句型： 条件从句 主句

过去完成时 should(would) have+ 过去分词

If she had worked harder, she would have succeeded

The rice would not have been burnt if you had been more careful

If my lawyer had been here last Saturday, he would have prevented me from going

If he had come yesterday, I should / would have told him about it

含义：He did not come yesterday, so I did not tell him about it

If he had not been ill and missed many classes, he would have made greater progress

含义： He was ill and missed many lessons, so he did not make greater progress

c 表示对将来的假想

句型： 条件从句 主句

一般过去时 should+ 动词原形

were+ 不定式 would + 动词原形

should+ 动词原形

If you succeeded, everything would be all right

If you should succeed, everything would be all right

If you were to succeed, everything would be all right

这是it引导的形式主语。真正的主语是后面that从句。

形式主语就是指真正的主语较长，为了让句式看起来平衡，先用it做了形式主语，真正的主语由that 或者to do引出。

除此之外，还有形式宾语，在动词后，由it引出

be walking on air的意思是“to feel extremely excited or happy”，即“欢天喜地，飘飘然”。

be walking on air这句习语的意思为什么是“欢天喜地，飘飘然”呢？

这句习语源于19世纪末。有人认为，这句习语之所以是这样的含义，是因为人高兴的时候，可能会觉得自己飘飘欲仙，就像飘在空中一样，所以这句习语表示的含义是“欢天喜地，飘飘然”。

例句：

Amy was walking on air after she got 100 in the test

艾米在那场考试中得了100分，高兴极了。

I have beenwalking on airsince I found out that I have been awarded a scholarship

自从得知自己获得奖学金后，我开心极了。

下面再介绍一个关于air的习语：in the air。

in the air的意思是“felt by a number of people to exist or to be happening”，即“可感觉到的”。

通常用这句习语来表示某种心情或感觉。可能是温度的变化，也可能是对某事正发生或将要发生的预期。这种感觉不一定是好的气氛，也可能是消极的气氛。比如某队输掉比赛，观众很不高兴，陷入了一种消极的氛围，这种氛围就可以用这句习语来描述。

例句如下：

There's romance in the air

有种浪漫的气氛。

The lights were low and romance wasin the air

灯光暗淡，弥漫着浪漫情调。

A，第一个考查的是虚拟语气的一个句型

if there were。。。。，there would be=were there 。。。。，there would be，即if引导的虚拟语气，谓语动词时were时，可以将were提前，省略if，表达的意思是如果没有空气，就没有声音。

D，考查的是修饰比较级的问题，这个句子要表达的意思是如果自来水像人们想得那么危险，我们中更多的人会生病的。 a lot 修饰比较级more， more of us 表示我们中更多的人。

看标点符号，这是考察感叹句。 填 How  这是感叹句的特殊用法。

How + 完整的句子 也可以表达感叹句。

eg 完整句子：    Time flies   时光飞逝。

      感叹句 How time flies！    时间过得多么快啊！

How I want to be an air-hostess！ 我多想当一个空姐啊！

shift键是开始键，也是游戏操作中的跳跃键，可以进行二段跳。Z键是武器发射键，在有存档的地方发射，即存档点红色变成绿色，表示存档成功。Q键是自杀键，R键是死亡后复活键，复活至上一个存档点。 希望能解决你的问题。