题目内容
句型转换
Tickets are cheaper if they are booked ahead of time.
Tickets are cheaper if they are booked _________ _________.
答案:in,advance
练习册系列答案
相关题目
题目内容
句型转换
Tickets are cheaper if they are booked ahead of time.
Tickets are cheaper if they are booked _________ _________.