A boy named Jacob was riding in a car along with his family. He was drinking a can(罐）of soda when his father drove the family home. After Jacob finished his soda, he rolled down （摇下）the window and threw the can out of the car.
After seeing what he did, his mother turned around to him and said, "Jacob! Don't throw your trash out of the car!
"But it was just one can…" Jacob replied.
"That may be so. But what if everybody did that?" she said. But Jacob didn't think much about her question. "
The next day, one of Jacob's classmates was celebrating her birthday in class. Her mother had brought a nice cake to class for everyone to share. But then Jacob came to the cake and licked off（舔掉）some of the frosting（糖霜）!However, Jacob's teacher noticed what he had done.
"Jacob!You shouldn't lick off frosting of a cake that everyone else is going to eat!" his teacher shouted.
"But it was only one lick…" Jacob replied.
"That may be so. But what if everybody did that?" she said.
This time, Jacob really did think about what would happen. If everyone licked the cake, it would be destroyed. If everyone threw trash out of their cars, the roads would be full of rubbish. It was then that Jacob realized how small actions can lead to big consequences（后果）.
