排序：

A. The zebra crossing is here. Let's cross the road.

B. Three, two, one. Here's the green light. Can we go and cross it now?

C. Look! There're so many cars and buses. How can we cross the road?

D. First, we must look for a zebra crossing.

E. Stop! It's red now. We must wait.
F. Sure. Let's go.