 Complete the following phrase:  In 1994, Chinese association football was professionalized, followed by basketball, volleyball, ping pong, and weiqi. Professionalization led to commercialization; this meant that sports associations became profit-making entities and that a club system and professional sports leagues were formed. Sports club operations now cover ticket sales, advertising, club transfers, commercial matches, and television broadcasting. Chinese athletes have also begun joining professional leagues abroad, such as basketball Yao Mings entry into the United States NBA in the 