Mr. Wang is a retired worker. He loves flowers very much. It was cold outside in winter, so he thought his flowers might be cold. He started the fire to heat a pot of water. After the water was boiling, Mr. Wang watered the flowers with it. He thought happily, Now it will be warm. But after a while, to his surprise, all the flowers died. Mr.Wang felt worried. From the story we know: No matter what we do, we must follow the natural rules.