a crow drinks water

One day, a small crow was thirsty. Looking for water everywhere, the crow saw a bottle with water inside, but there was not much water in the bottle, the bottle was very small, and the crow could not drink water. What should I do?

The crow thought about it. Suddenly, I saw many small stones beside the bottle and came up with a solution.

The crow put the stones one by one into the bottle, the water gradually rose, and the crow drank the water.

Second grade of Haibei Elementary School, Nanhai District, Foshan, Guangdong: 1076613777