Lisa: Look, James. There is a lake in the park.
James: It's beautiful. Can we swim there?
Lisa: No, we can't. The sign near the lake means we can't swim here.
James：I see. Look at the sign on the grass. What does it mean？
Lisa：It means we can't litter here.
James：The flowers are beautiful. Can I pick one？
Lisa：No, you can't. Look at the sign.
James：What does it mean？
Lisa：It means we shouldn't pick flowers.
James:I see.（仅供参考）
