關於專升本英語，同學們在做完形填空題時，最忌在對文章似懂非懂的狀態下，僅憑孤立的語法和詞彙關係，草草圈定答案。我們應持的態度是，務必注意對文章主旨的`理解，注意對上下文線索的追蹤回顧，注意前後照應，並將語境、語義與語法、詞彙的搭配，通盤進行考慮。說起來容易，做起來難，小編先給大家總結一下完型填空中經常考的重點句型，大家學習學習，用來備考英語完型填空。
一、It 作形式主語
1、It is + 名詞/形用詞/過去分詞 + that 從句 (主從) = that 從句 (主從) is +名詞/形用詞/過去分詞
It is well known that + 句子(眾所周知)
It is obvious that + 句子 (明顯的)
It is apparent that + 句子 (顯然的)
例句：It is well known that diamonds are the hardest substance.
例句：It is universally acknowledged that trees are indispensable to us
全世界都知道樹木對我們是不可或缺的.
例句：It is common knowledge that honesty is the best policy.
2. It is + 形容詞/過去分詞/名詞 (for sb.)+ to do …
例句： It is hard (for me)to finish the work in three days.
It is an honor to meet you.
was said/reported/ thought/believed + that從句(主從) 據說/報道/認為…
Sb. was said/reported/ thought to do …
例句：It was said that he had been killed in the accident.
此句子可以轉化為：He was said to have been killed in the accident.
4. It took/ will take sb. + time to do … 某人花費時間幹…
例句：It took me 10 days to finish my paper.
二、It 表示時間的常用句型
is/has been+一段時間+since... "自從...已有多久"
since後的從句用一般過去時
It has been two weeks since he left
他已經離開了兩個星期了
was+一段時間+before... "在...之前過了多長時間"
before 後的從句用過去完成時
It was three years before he had finished his research
在他完成他的研究之前已經過去三年了
will be+一段時間+before... "過了多久才..."
before後的從句用一般現在時
It will be two days before she arrives at Britain
兩天後她才會到達英國
