The book you borrowed from the library should been returned in five days.
问题描述：
The book you borrowed from the library should been returned in five days.
那什么.为什么不是The book you borrowed from the library should be returned in five days.为什么是“been”不是“be”?
答
有两种可能：
1 The book you borrowed from the library should be returned in five days.（指将来）
2 The book you borrowed from the library should have been returned five days ago (指过去)