Recently, Zhang Jian, a chemistry teacher at Wugang Third High School in Wuhan, posted a picture online, which shows the 100 red pen refills that he used to correct his students' homework in one year. (Photos: Chinanews)

Zhang says it takes him nearly two hours to correct students’ homework every morning.

He marks error-prone exercises and writes thoughtful comments on their assignments.

These used-up red pen refills show this teacher's respect for his students' hard efforts.

This picture shows his collection of used-up red pen refills. That's about twice the amount teachers usually use in a year.

Zhang teaches chemistry in class.

Zhang helps students with chemistry exercises patiently.

Zhang hopes that his students will get good grades in the coming national college entrance exams.