Students jog on the newly built track on a building roof in the Second Primary School of Chicheng Street in Tiantai county, Zhejiang province on Sept 1, 2014. The 200-meter-long track was built on the roof because of a lack of construction land on the campus and is the first case of its kind in the country. The track can meet the needs of 1600 students for physical education, the head of the school said. [Photo by Sun Jinbiao/Asianewsphoto]