阅读下面对话，从方框中选择适当的句子补全对话。

A:  What book are you reading, Sally?

B:     46   

A:  English is your favorite, right?

B:  Yeah, it’s easy and interesting.   47   

A:  I don’t like it.   48   I like history very much because it makes us wise.

B:  My history is not good.    49   

A:  Good idea.

B:     50    Let’s go.

A:  OK.