1. Beautiful ripples are drawn on the mirror-like lake. Ripples go round and round, gradually expand, and then quietly disappear.

2. At first, the fluctuation of water molecules was generated only at the place where energy was received, and later, even the water molecules around the water molecules were driven up, thus forming layers of ripples outward.

3. Suddenly, the water splashed, and ripples appeared on the water surface, and the ripples continued to spread around.