Children greet 2018 National Science Day across China

A staff member introduces knowledge of colorful silkworm cocoon to children and their parents at Beipei District in Chongqing Municipality, southwest China, Sept. 15, 2018. Various activities are scheduled to be held from Sept. 15 to Sept. 21 across China to greet the 2018 National Science Day held each year. (Xinhua/Qin Tingfu)