Roger Federer of Switzerland serves to Karen Khachanov of Russia during the match between Switzerland and Russia at Hopman Cup mixed teams tennis tournament in Perth, Australia, Jan. 2, 2018. Roger Federer won 2-0. (Xinhua/Zhou Dan)
In pics: Hopman Cup mixed teams tennis tournament
Source: Xinhua| 2018-01-02 19:38:23|Editor: Chengcheng
