1、There be结构。
例句：There is no sense(道理)in leaving important decisions to inexperienced people.
2、It 结构。
例句：It is necessary that young and old people should communicate more with each other.
It took the human race millions of years to attain that record.
3、递进式结构。
例句：They do not seem to like one anther very much. Neither are they too keen on conventional people (正统的人).
4、主语从句结构。
例句：What makes it rather disturbing (令人烦恼) was the arbitrary circumstances both of my arrest and my subsequent fate in court.
5、中间段落拓展句型。
描述原因的'句型：due to /because of /for the reason that
The chief reason why… is that …
描述结果的句型：Thus/Asa result/So/Consequently/Hence/Accordingly/Thereby…
论证说明句型：It is obvious / apparent/ clear/ conspicuous / without doubt that…
