学习目标
By the end of the class, the students will be able to:
Use perfect continuous
学习过程
课堂活动
（一） 预习交流
perfect continuous
（二） 合作探究
1. — I’m sure Andrew will win the first prize in the final.
— I think so. He ________ for it for months. (2008江苏)
A. is preparing B. was preparing
C. had been preparing D. has been pre paring
