一、以it作主语的强调句型：it is / was….that / who….，强调部分可以是句子的主语、宾语或状语。此句除了谓语动词外其他成分都可强调。若强调部分是人，可用that或who；若强调其他成分，则只能用that。例：
1. When I try to understand ___that prevents so many Americans from being as happy as one might expect, it seems to me that there are two causes.
A. why it does     B. what it does   C. what it is    D. why it is
    本题属it is…that强调结构，that句中的prevents缺少主语。本题答案为C。全句意为：“当我试图搞明究竟是什么使得美国人不能如人们所期望的那么幸福生活时，我似乎找到了两个原因。”
2. _______she first heard of the man referred to as a specialist.
A. That was from Stephen      B. It was Stephen whom
C.It was from Stephen that     C.It was Stephen that
    C对，全句意为：“她是从Stephen那儿第一次听说被称为专家的那个人”。也属于it is…that句型。
3. ______that the trade between the two countries reached its highest point.
A. During the 1960’s                B. It was in the 1960’s
C. That it was in the 1960’s         D. It was the 1960’s
    B对，全句意为：“就在20世纪60年代，两国之间的贸易达到了最高点。”
    二、运用本身含强调意味的词汇加以强调，如very，right，do/does等。例：
This is the very book I’m looking for.
Do phone me when you arrive.