not as as 和not so as的区别
not as as与not so as意思上是一样的，都是“与……不一样”的意思。
not as as语气略弱，not so as语气略强。但是在肯定句中只能用as...as不能用so...as。
You are not as tall as he.
你没有他高。
His Arabic was not as good as his English, but serviceable enough
他的阿拉伯语没有他的英语好，但是够用了。
It is not so expensive as you might expect.
那不像你料想的那么昂贵。
This bike is not so good as that one.
这辆自行车不及那辆好。