选择句子，完成对话。

A. Do you want to go with us? B. I'm going to buy a travel book(旅游书). C. What are you going to do this weekend, Sam? D. Qingdao is a wonderful place for a holiday.

Dad: Today is Friday.

Sam: I don't have any plans.

Dad: Mum and I are going to a book fair (书展) on Sunday.

Sam: Sure. I like reading books.

Mum: Will you buy some new books?

Sam: Yes.

Dad: That's good. Do you have any plans for our summer holiday?

Sam: How about taking a trip to Qingdao, Dad?

Dad: Good idea.

Mum: Let's buy a travel book about Qingdao and plan our trip.