以下是一些成考英语补全对话常用的句子：

1. Good morning/afternoon/evening. How are you today?

早上/下午/晚上好。你今天怎么样？

2. I'm fine, thank you. And you?

我很好，谢谢。你呢？

3. I've been busy with work lately.

最近我一直很忙。

4. What's your major?

你学的是什么专业？

5. I'm studying for the college entrance examination.

我正在准备高考。

6. Do you have any plans for the weekend?

你周末有什么打算吗？

7. I'm going to visit my family in the countryside.

我要去乡下拜访我的家人。

8. I'm planning to go hiking with some friends.

我打算和几个朋友去徒步旅行。

9. How do you like this city?

你喜欢这个城市吗？

10. It's quite beautiful, especially during the spring.

这里很美，尤其是春天。

11. Do you have any suggestions for places to visit?

你有什么推荐的景点吗？

12. I think the museum is a must-see.

我认为博物馆是非去不可的地方。

13. I'm not sure about the food here.

我对这里的食物不太了解。

14. I heard the local cuisine is quite delicious.

我听说这里的当地美食很美味。

15. I hope you can help me improve my English.

希望你能帮助我提高英语水平。

16. I'm trying to learn more about American culture.

我正在努力了解美国文化。

17. Have you ever traveled abroad?

你出过国吗？

18. Yes, I went to Japan last summer.

是的，我去年夏天去了日本。

19. I'd love to hear about your travel experiences.

我很愿意听听你的旅行经历。

20. It was an unforgettable trip.

那是一次难忘的旅行。