 Complete the following phrase:  Zhou became a coach of the Chinese national team in 1973, and trained several male and female world champions, including Cao Yanhua, Guo Yuehua, Chen Xinhua, Zhang Deying, and Qi Baoxiang. In Cao Yanhuas memoirs, she called Zhou almost a devil, and recalled that though she fainted several times during training, he made her continue practicing after she regained consciousness. His training regimen was highly effective though, and Cao won her first national championship after only two months of training under Zhou, which she called miraculous. She went on to win multiple gold medals in world championships, and after winning two gold medals at the 