Ⅵ.补全对话
（在下面对话的空白处填上适当的话语，使对话完整。话语可能是句子、短语或单词。)
A: Hello, Henry, you look unhappy. 76 ?
B: Hello, Molly, I have to write a report about the most useful invention for my history class.
A: That’s not too difficult.
B: But I have to hand it in tomorrow.
A: You’d better hurry up. 77 ?
B: I’m going to write about the computer.
A: Maybe everybody is going to write about that. 78 write about some older things, like clocks?
B: That’s a good suggestion! But I don’t know much about that.
A: Don’t worry. 79 .
B: Really? It’s very kind of you. 80 .
A: You’re welcome.