1. not if相当于 如果。。。就不。。。
例如 :-I think if John insists on going to the States, we have to find someone else to replace him.
--Not if I can talk him out of it.
如果约翰坚持要去美国的话,我们就得找人替代他了
如果我能说服他不去,我们就不必找人了
2. whether conj.
(引导名词从句)是否
Ask him whether he can come or not.
问问他是否能来。
I don't know whether you like flowers, sir.
先生,我不知道您是否喜欢花。
3. as good as
1. 和...几乎一样
It was as good as new.
这几乎像新的一样。
提问者对于答案的评价:as good as 前后可跟名词?