Imitate crows drinking water and talk about the difficulties we encounter in reality and how to solve them

1. If a ping-pong ball falls into a small hole, you can fill it with water and let the ping-pong ball float with the help of the buoyancy of the water (the prerequisite is to make sure that the hole is not bottomless and not very deep);

2. A man accidentally fell into a cave. The entrance of the cave was not very deep, but it was taller than the man. Then he piled stones together, stacked them up layer by layer, and then climbed out by stepping on the stones. outside the cave.