Girls attend an artistic grade examination at an adolescent practice and education base in Lhasa, capital of Southwest China's Tibet autonomous region, Aug 4, 2017. A social artistic grade examination organized by China National Opera and Dance Drama Theater was held here on Friday. The exam, including music and dance categories, will last until Aug 6. [Photo/Xinhua]

Girls attend an artistic grade examination at an adolescent practice and education base in Lhasa, capital of Southwest China's Tibet autonomous region, Aug 4, 2017. [Photo/Xinhua]

A child makes preparation for an artistic grade examination at an adolescent practice and education base in Lhasa, capital of Southwest China's Tibet autonomous region, Aug 4, 2017. [Photo/Xinhua]

Children make preparation for an artistic grade examination at an adolescent practice and education base in Lhasa, capital of Southwest China's Tibet autonomous region, Aug 4, 2017. [Photo/Xinhua]

Girls attend an artistic grade examination at an adolescent practice and education base in Lhasa, capital of Southwest China's Tibet autonomous region, Aug 4, 2017. [Photo/Xinhua]