Prompt: Ma Guang was born in Guangshan, Guangzhou (now Xinyang City, Henan Province). Once, he was playing in the backyard with a few friends. There was a naughty child who climbed onto a large water tank, but lost his footing and fell into it. The water tank was deep and the children were small. Seeing that their friends were about to drown, the other children were frightened. Some children were so frightened that they cried, and some were so frightened that they went to look for adults. At this moment, Sima Guang suddenly became wise, picked up a big stone from the ground, and hit the water tank with all his strength. Through Sima Guang's smashing of the vat, water gushes out and the friend is saved.