carbon dioxide；1957；1997；increase/ went up；per

Step2 Grammar

强调句结构

常考的强调句结构是it 引导的句子。

It is (was) 被强调部分+ that (who) + 句子其他部分。此结构强调的成分仅限于主语，宾语和状语。

It is from the sun that we get light and heat.

It was not until I had read your letter that I understood the true state of affairs.

Karl bought Marva a bicycle on her birthday．卡尔在玛瓦生日那天给她买了一辆自行车。

It was Karl that／who bought Marva a bicycle on her birthday．（强调主语）

It was Marva for whom Karl bought a bicycle on her birthday．（强调间接宾语）

It was a bicycle that Karl bought Marva on her birthday．（强调直接宾语）

注意区别强调句中的that／who分句与定语从句：

It was the student that／who asked the silly question．是一个学生问了这么一个愚蠢的问题。（分裂句）

He was the student who asked the silly question．他就是问了这么一个愚蠢问题的学生。（划线部分是定语从句）

二、not ... until ... 的强调形式: It is not until + 被强调部分 + that ... "直到...才..."， 主要用于强调时间状语的强调句型。

We did not begin studying French until we entered university．我们进了大学才开始学法语。 要强调until we entered university，就成了：

It was not until we entered university that we began studying French．

______ the 18th century that man realized that the whole of the brain was involved in the workings of the mind．

A. During B. In C. It was until D. It was not until

D对。直到十八世纪，人们才意识到：心理活动与整个大脑有关。

三、强调句的疑问句句型

1.强调句的一般疑问句句型:

Is / Was +it +所强调的部分+that / who/ whom +其它?

2.强调句的特殊疑问句句型:

特殊疑问词 + is/was it that / who/ whom+其它 ?

Why is it that you hate winter？你究竟为什么不喜欢冬天？

How was it that you missed such a wonderful lecture？你怎么会错过这么精彩的报告？

When was it that they went abroad？他们什么时候出国的？

四、判断强调句的方法

判断是否是强调句是，可把 It is / was ...that 去掉，剩余部分在不增减任何词的情况下还是一个完整的句子，那么这种句子是强调句。

It was in the street that I met her father.

→In the street I met her father.

It was because she was ill that they didn't ask her to do the job.

→Because she was ill, they didn't ask her to do the job.

Step 3 Exercises

一、根据划线部分把下列句子变成强调句。

1. Peter lent us the money.