英语六级考试阅读模拟练习题(21日)

　　1.What is the topic of the passage?

　　2.Where was ice used after the Civil War?

　　3.What was essential to a science of refrigeration according to the passage?

　　4.It can be inferred from the passage that the theoretical foundation of ice box should be that____________.

　　5.Without an ice box，farmers had to go to the market at night because_______.