Prep2-8

Ozone, a special form of oxygen that screens out harmful ultraviolet rays,

reaches high concentrations twelve miles above Earth, where it has long

appeared that it was immune from human influence; we have now realized,

though, that emissions of industrial chlorofluorocarbons deplete the ozone

layer.

(A) has long appeared that it was immune from

(B) has long appeared to have been immune from

(C) has long appeared as being immune to

(D) had long appeared immune to

(E) had long appeared that it was immune to

ans D

我想问的是形式主语的问题 题中where it has long ...的it形式主语指代的是什么啊？

一到形式主语我就有点犯晕~

形式主语(先行主语)，形式主语it指代句子后真正主语

强调结构，It beV.+强调部分+who(m)或that+其它部分

强调结构中it不做句子结构中的任何成分，无所指代，故不与后面的it冲突

顶~~~

有没有人可以帮忙一下

到底形式主语会不会跟后面的it产生指代不清

1.这里是不是什么形式主语或者形式宾语，它就是真正的主语，ozone。

2，appear解释看起来好像的时候，后面直接+形容词。i appear happy

3,immune to固定词组