Amy: Hello, Tim.
Tim: Hi. Amy.
Amy: It's Saturday tomorrow.？
Tim: I'm going to finish a report.
Amy: Really?？
Tim: It's about water pollution. The river here is really dirty.
Amy: That's too bad.. I used to swim in the river.
Tim: If we do nothing, the water pollution will be more serious. So I want to do a survey to get some information for my report.？
Amy: Sure, I'd love to. Let's do it together. When shall we do?
Tim: How about tomorrow afternoon? Let's meet at three o'clock at the school gate.
Amy: OK. I'll be free then.
