从方框中选择恰当的句子补全对话。

A. How are you going there? B. We're going to Shanghai. C. What are you going to do there? D. When are you going? E. Why not go there on Saturday?

A: Where are you going this weekend?

B:

A: Oh，great!

B: We're going to visit my grandparents.

A:

B: We're going by train.

A:

B: On Friday.

A:

B: Because Saturday is my grandpa's birthday.