在双打中，每次换发球时，前面的接发球员应成为发球员，前面的发球员的同伴应成为接发球员。也就是说，在一局比赛中，只要涉及到换发球，原发球方两名队员要求交换位置。
In doubles, at each change of service the previous receiver shall become the server and the partner of the previous server shall become the receiver. In other words, as long as a change of serve is involved, the two players of the original server need to change positions. 
A、正确
B、错误