1. Goodbye!

2. Bye!

3. See you!

4. See you later!

5. See you soon!

6. Catch you later!

7. Bye-bye!

8. Farewell!

9. Take care!

10. So long!

11. I'm afraid I must say goodbye.

12. The time has come to say goodbye.

13. I've come to say goodbye.

14. I'd like to say goodbye to you.

15. I'm really going to miss you.

16. Goodbye, it was nice seeing you.

17. Goodbye, have a safe trip.

18. Goodbye, take care.

19. Goodbye, but not forever.

20. The road ahead is long, but let's keep in touch.

21. May the road rise up to meet you, and the wind be at your back.

这些短句可以根据不同的场合和与不同的人之间的关系进行选择和使用。