YOU’RE on the school bus. But as soon as you turn the corner, you find yourself at the end of a very long queue. It’s another traffic jam! It is stop-start for the rest of your journey. Meanwhile, at the same time in Antarctica (南极洲), snow blankets the land. A group of emperor penguins crowd together to keep warm, using stop-and-go movements to protect themselves from the winds. Can you see the connection?