补全对话。

A. It's a green light. B. Hello, Tom! C. How do you go to school? D. Do you know the traffic lights?

Amy:

Tom: Hi, Amy!Let's go to school.

Amy: OK.

Tom: Usually I go to school on foot. Sometimes I go to school by subway.

Amy:  

Tom: Yes, I do. Stop at a red light. Go at a green light. Wait at a yellow light.

Amy: You are right. Look! Let's go!