China's top 10 science and technology stories in 2021.

A group from the University of Science and Technology of China in Hefei used rare earth ion-doped crystals to test the world's first quantum repeater segment based on absorptive quantum memories, and achieved the longest, record-breaking optical storage time of 1 hour. A list of the top 10 domestic science and technology stories was jointly released by the Chinese Academy of Sciences and the Chinese Academy of Engineering in Beijing on 18 January 2022. Graph: Tianwen-1, China's first mission to Mars, was decalred a success. [Extracted from the article]