如题所述
第1个回答 2010-09-19
1. 用it或用it's都是可以的。
2. 如果用it's，则使用一个省略that的宾语从句，且宾语从句的结构是一个固定句型：it is + 形容词/名词 + to do sth.
即：I think it's bad manners to smoke in a reading room.
= I think (that) it is bad manners to smoke in a reading room.
I think it's impolite to smoke in a reading room.
= I think (that) it is impolite to smoke in a reading room.
3. 如果单独使用it，则采用了以下固定结构：
及物动词think + 形式宾语it + 宾语补足语（名词/形容词）+ 真正宾语（不定式）。
因为做宾语的不定式太长，放在中间会显得此句头重脚轻，所以一般将其后置，并使用it去做形式宾语。
类似的动词有五个：think, feel, make, find和consider.
再如：I find it difficult to learn English well.
= I find (that) it is difficult to learn English well.
2. 如果用it's，则使用一个省略that的宾语从句，且宾语从句的结构是一个固定句型：it is + 形容词/名词 + to do sth.
即：I think it's bad manners to smoke in a reading room.
= I think (that) it is bad manners to smoke in a reading room.
I think it's impolite to smoke in a reading room.
= I think (that) it is impolite to smoke in a reading room.
3. 如果单独使用it，则采用了以下固定结构：
及物动词think + 形式宾语it + 宾语补足语（名词/形容词）+ 真正宾语（不定式）。
因为做宾语的不定式太长，放在中间会显得此句头重脚轻，所以一般将其后置，并使用it去做形式宾语。
类似的动词有五个：think, feel, make, find和consider.
再如：I find it difficult to learn English well.
= I find (that) it is difficult to learn English well.
