This is a pinyin poem:
Mushrooms come out wearing straw hats;
It's raining and the ground is bubbling. Mushrooms come out and put on a straw hat. _ Little Rabbit jumped for joy when he saw it. Holding a small basket, laughing while picking it!
When it rains in the sky, bubbles appear on the ground: because the specific gravity of air is smaller than that of water and the land contains gas, the water will sink and the gas will float, so bubbles will form. Another possibility is that raindrops quickly hit the water surface after water accumulates on the ground, and air will also form bubbles when it enters the water.