we'll join them for dinner___they ask.

问题描述:

we'll join them for dinner___they ask.
为什么是should,不是shall,是虚拟,为什么前面有用will

这种属于错综时间条件句.其中条件从句是虚拟语气,而主句表达的却是真实条件句.我们也可以把句型颠倒一下:Should they ask,we'll join them for dinner.其中,"should they ask"是省略了“if”的倒装结构,完整的句子...