Tennis star Peng Shuai is still missing. Serena Williams, Naomi Osaka, and the WTA demand answers.

Chinese tennis player Peng Shuai hasn't been seen since publicly accusing government official Zhang Gaoli of sexual assault.

On Nov. 2, Peng made allegations against the former vice premier of China in a lengthy Weibo post, which was deleted half an hour later, CNN reports.

In the post, Peng alleged that Gaoli had sexually...