Doo Hoi Kem of Hong Kong, China, serves during the U21 women's singles final against her teammate Soo Wai Yam at the ITTF Seamaster 2017 World Tour Platinum Qatar Open, in Doha, capital of Qatar, Feb. 22, 2017. Doo Hoi Kem won the final 3-1 and claimed the title of the event.(Xinhua/Nikku)