---I have booked my ticket back to Washington. My flight leaves at 9:00 tomorrow morning.-

问题补充：

---I have booked my ticket back to Washington. My flight leaves at 9:00 tomorrow morning.

---.

A. Is that so?

B. How wonderful!

C. Have a good trip.

D. Well, goodbye.

答案：

A. Is that so?

B. How wonderful!

(答案→)C. Have a good trip.

D. Well, goodbye.

解析：情景交际。A. 真的是这样吗? B.太美妙了! C. 祝你旅途愉快. D. 好吧，再见。句意：我已经顶了会华盛顿的票。我的航班在明天上午九点起飞。结合语境可知选C为最佳答案。