it 作形式主语（英语专业的请进）,选哪个：I think( ) is not good to smoke in public.A.this B.that C.it D.youit 作形式主语要具备什么条件,它前面可以是那些词,例如：I found it's interesting to play sports.I think it's interesting to play sportsI belive it's interesting to play sportsI feel it's interesting to play sports以上句子可以吗?在found、think、belive、feel 这些词之后的it 作主语和宾语都可以吗?有什么决定它作主语还是宾语?（我求知心切,请答得具体点,）
问题描述：
it 作形式主语（英语专业的请进）,
选哪个：I think( ) is not good to smoke in public.
A.this B.that C.it D.you
it 作形式主语要具备什么条件,它前面可以是那些词,例如：
I found it's interesting to play sports.
I think it's interesting to play sports
I belive it's interesting to play sports
I feel it's interesting to play sports
以上句子可以吗?在found、think、belive、feel 这些词之后的it 作主语和宾语都可以吗?有什么决定它作主语还是宾语?
（我求知心切,请答得具体点,）
答
在这道题以及你写的这些句子里面,think, found, believe, feel后面接的都是一个宾语从句,如果写完整的话应该是: I think that it is not good to smoke in public. 原句中把that省略掉了,这是允许的.而后面这个从句中it 是作为形式主语,避免句子头重脚轻.
如果要改写成it做形式宾语的句型,可以写成：
I think it no good/bad to smoke in public.
I found it interesting to play sports.
在这里面it 后面就不要有be动词了.
希望帮到你!