问题描述：
关于it的用法
1:Someone is knocking at the door .Go and see_____.
为什么选：who it is 而不是who is it
4:--why don't we take a little break?
----Didn't we just have ___?
为什么是用one 不用it?
1:Someone is knocking at the door .Go and see_____.
为什么选：who it is 而不是who is it
4:--why don't we take a little break?
----Didn't we just have ___?
为什么是用one 不用it?
问题解答：
我来补答展开全文阅读