People's Liberation Army Astronaut Corps twelve were chosen as astronaut candidates. The Astronaut Corps was established in January 1998 and the twelve along with two PLAAF trainees sent to Yuri Gagarin Cosmonaut Training Center in 1996 forms Chinese Group 1. Seven pilots entered the Astronaut Corps in May 2010 as the Group 2. In 2014, Group 1 astronauts Wu Jie, Li Qinglong, Chen Quan, Zhao Chuandong, and Pan Zhanchun retired from the Astronaut Corps due to age; none of them had flown in a mission. The Astronaut Corps was part of the General Armaments Department until GAD's disbandment in January 2016. As part of the
Chinese as a foreign language neutral (轻声，denoted as no-mark in Pinyin) although the official name of the tones is Four Tones. Many other Chinese dialects have more, for example, Cantonese has six (often numbered as nine, but three are duplicates). In most Western languages, tones are only used to express emphasis or emotion, not to distinguish meanings as in Chinese. A French Jesuit, in a letter, relates how the Chinese tones cause a problem for understanding: Moser also stated that tones were a contributing factor to the difficulty of learning Chinese, partly because it is difficult for non-native learners to know how to convey emotion