读对话，完成句子。

A: are you going this afternoon?

B: I am going to the bookstore.

A: ?

B: I'm going to buy a dictionary.

A: are you going?

B: I'm going at 4 o'clock.

A: are you going there?

B: I'm going there by bike.

A: are you going with?

B: I am going there with my sister.