根据对话内容，在空白处填恰当的句子，使对话完整、通顺

(in the office)

A: Alex do you have any exciting plans for the weekend?

B: Yes, I do, Ben. I'm going to go kayaking (划皮艇).

A: Kayaking! That sounds fun!?

B: No, but I can rent (租用) a kayak. It's not too expensive.

A: ?

 B: I' m going to kayak down Old Mill River.

A: Be careful! That's a fast river! ?

B: With my friends Bob and Joe(later)

C: I hear

B: Yes, I am. I can't wait. Kayaking is really fun.

C: I know it's-exciting, but it can be dangerous. ?

B: I'll wear a helmet (头盔) and a life jacket.

C: That's good. Have a good weekend!