No one can change the weather. But if we read the signs around us correctly, we can tell how the weather will be. This way of telling what the weather will be like on the following day or two is called weather forecasting. For many centuries and in all countries, people have studied the weather and tried to make weather forecasting. Rings around the sun are a sign of coming rain. Many people feel in their bones the coming of wet weather—they feel joints (关节). Some birds fly high if fine weather is coming, but they fly near the ground if rainy or stormy weather is on the way. It is probably because of the insects which they are hunting that they fly low. If you see a rainbow during rainy weather, this is a sign that the weather will become clear and fine. Such rainbows come in the evening. If the stars twinkle (闪烁), then fine weather will continue. If a fog appears in the morning just above a river, then the day will be warm. If the sunset is mostly red in colour, rainy weather will probably come. Most of the above sayings have been made by the people who have used their eyes and brains to make weather forecasting.