英语提问:for how long与how long的用法区别?For how long did he stay here?How long did he stay here?加介词和不加介词有什么区别?什么情况下可以用介词+疑问词结构?

问题描述:

英语提问:for how long与how long的用法区别?
For how long did he stay here?
How long did he stay here?
加介词和不加介词有什么区别?什么情况下可以用介词+疑问词结构?

没啥大的区别 习惯上用第二种税法