Use examples or comparisons to illustrate a solar term, about 50 words.

Wan Li is clear, Wan Li is cloudless and sunny. My little sister and brother are playing on the grass, and my heart is full of joy. A cold wind blew on their faces like a knife, and there was no sun for ten years. How painful it is for children to look up at the sky from the window! We should protect the environment, starting with me, and everyone is responsible.