what are their favorite sports?
【他们】和【她们】在英语里没有区别.谢谢，那个their可以换成they吗？肯定不可以啊。they是主语，这里要用属格their表示【他们的】。还可以这么说：what are their favorite sports？或what are the favorite sports of theirs？后面的说法有点罗嗦，美国人一般说第二种。