Astronauts pose for group photos with audience during a sharing session at the Chinese Foundation Secondary School in Hong Kong, south China, June 28, 2017. The sharing session highlighting China's development and achievement on aerospace science and technology was held here on Wednesday to celebrate the 20th anniversary of Hong Kong's return to the motherland. Chinese astronauts Yang Liwei, Jing Haipeng and Chen Dong participated in the session to interactive with more than 800 teachers and students. (Xinhua/Lui Siu Wai)