Kaitlyn Christian (R) of the United States and Carina Witthoeft of Germany return the ball during the women's doubles second round match against Gabriela Dabrowski of Canada and Xu Yifan of China at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Kaitlyn Christian and Carina Witthoeft lost 0-2. (Xinhua/Chen Yichen)