题目内容：

补全对话

根据下面的对话内容，在横线上填入恰当的句子，使对话通顺，结构完整。

A: Hello, Cindy! 1.________________________

B: I’m fine, thanks.

A: 2._______________________

B: My favorite subject is science.

A: 3.________________________

B: Because it’s difficult but interesting.

A: 4.________________________

B: Mr. Lin is my science teacher. We like him very much.

A: Oh, Mr. Lin. Today is Friday. It’s Mr. Lin’s birthday. I know he’ll have a

birthday party tonight.

B: Let’s go to his birthday party.

A: 5.________________________