During the Jin Dynasty （晋朝），there was a child named Che Yin. He was intelligent and loved reading. He grew up in a poor family and couldn't afford lamp oil（灯油） to study at night.
One night，he saw fireflies（萤火虫） outside his house and came up with an idea. He caught some fireflies in a cloth bag and hung the bag up as a lamp. It was said that he spent all of his summer nights reading like this.
Another child named Sun Kang who lived during the same period also loved reading. One night during winter，Sun used up all of his lamp oil and couldn't study at night. When he suddenly woke up at midnight，he saw the snow reflecting the moonlight outside his house. His first thought was "Oh，I can use the reflected light to read!" He took out his books and read，even though he was freezing cold.
Both of the two kids later became successful government officials（官员）. People were touched by their hardworking spirit and their stories inspired the Chinese idiom （成语） "nangying yingxue（囊萤映雪）"，or "to read by the light of bagged fireflies or the reflected light of snow".
In the past，people had a harder time studying than we do now. They had to copy books by hand because books were valuable back then. For poor families，paper and writing brushes were too expensive to afford. Students even had to travel over mountains and rivers in order to find a good teacher. However，these difficult situations did not stop young people from pursuing（追求） knowledge.
