People need fire. Fire is useful, but sometimes it is harmful (有害的). So we should use fire correctly (正确地).
We use fire to cook food. If we eat raw (生的) meat, we may get ill. Fire gives us heat. In winter, we can make a fire and get heat.
But sometimes fire is dangerous. It can burn down a lot of things. It can kill (杀死) people with smoke. So we shouldn't play with fire.