In pics: women's singles first round at 2019 US Open

Karolina Pliskova of the Czech Republic hits a return during the women's singles first round match between Karolina Pliskova of the Czech Republic and Tereza Martincova of the Czech Republic at the 2019 US Open in New York, the United States, Aug. 26, 2019. (Xinhua/Liu Jie)