The librarian asked him to return the book_____

题目

The librarian asked him to return the book_____
A.in one day or two B.for one or two days C.within one day or two days D.in a day or two
A 和C为什么不对

答案

语法上没什么错.只是人们习惯上会说：
A. in one or two days
C. within one or two days