One possible version
Dear editor,
It can be seen easily from the above chart that American students 72 minutes on physical activities per day, and those in South Korea 42 minutes. However, Chinese students have only 12 minutes for physical activities per day.
The reasons lie in the following. Almost all the time is spent on lessons in Chinese schools and students are made by parents to concentrate on their study even when they get back homes. Thus there is little time left for their physical activities.
In my opinion, both the Education Departments and parents are responsible to give the students more time for physical activity. Anyhow, knowledge can be learned not only from books but also through activities.
略