China science, technology news summary -- Nov. 21

BEIJING, Nov. 21 (Xinhua) -- The following is a summary of published science and technology news of China.

25TH ANNIVERSARY

China's astronauts aboard the Shenzhou-19 crewed spaceship recorded a video on Wednesday to celebrate the 25th anniversary of the successful launch of Shenzhou-1, the country's first experimental crewed spaceship launched on Nov. 20, 1999.

The Shenzhou-19 crew members, Cai Xuz