问题描述：
Will we need to show our passports?
What do we need to take for the picnic?两个都是need to do 为什么一个加do做助动词,一个不要
What do we need to take for the picnic?两个都是need to do 为什么一个加do做助动词,一个不要
问题解答：
我来补答展开全文阅读