---I went to Paris on my vacationA. Can I join you?B. Have a good time.C. Really?How

问题补充：

---I went to Paris on my vacation.

---

A. Can I join you?

B. Have a good time.

C. Really?How was it?

D. Good idea.

答案：

A. Can I join you?

(答案→)B. Have a good time.

C. Really?How was it?

D. Good idea.

解析：在英语中，当我们听到别人将要去某地时，我们应该表示祝福祝愿说：Have a good time。所以本题选B。