Ding Yiyi heard the call for help, changed her original idea of returning to the car, followed the sound source, she came to a pond in the park.

There were several children in school uniforms in front of the pond. When they saw Ding Yiyi, they hurried and said, "Our classmate fell into the water. He can't swim."

Ding Yiyi looked to the lake. The fence beside the lake had been torn open. It said, "The lake is two meters deep. Please don't paddle and so on. It's all scribbled up."

There is a boat in the middle of the lake. There are only slight ripples on the water beside...