113　as...as的否定式有几种

　as+形容词或副词原级+as 意为“同……一样”，表示同等比较，它的否定式可有两种形式：

不如……

not so...as

not as...as

This box is as big as that one. 这个盒子同那个盒子一样大 。

This box is not so big as that one. 这个盒子不如那个盒子大 。

She sings as well as Mary. （正）她唱得同玛丽一样好 。

She doesn't sing as well as Mary. （正）她唱得不如玛丽好 。

She sings as better as Mary. （误）

She sings not as well as Mary. （误） （应否定谓语 ）