A: Rob, you look upset!
B: I'm worried about Mr. Smith.
A: Where is he?
B: Maybe he is hurt. Look at his desk.
A: Oh, there are papers everywhere. There is some bread his desk.
B: And there is some coffee on the desk, too.
A: See? Something bad might have happened.
B: Oh, Betty. I just touched the coffee. It is still hot.
A: He must be nearby
B: Oh, there some coffee on my hand. I need a tissue(纸巾).
A: But the box is empty.
B: You can find some in the next-door office.
A: Oh, the door is locked. But I can hear something inside.
B: Let's with the key and have a look!
A: Oh, Mr. Smith is here. He is sitting on the chair and thinking about something.