Know the weather from the clouds.

Seeing the weather from the clouds is an explanatory article in middle school students' Chinese. It is a description of specific things.

The key word of this sentence is: "Look at the shape, color and thickness of clouds, and then identify the weather's wind, frost, rain and snow."

Please take out the specific sentence of the article "Looking at the weather from the clouds", which is usually the beginning or the end. The beginning of each paragraph is a central sentence.