Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

A Chinese woman wears a mask to protect from particles blown in during a sandstorm as she walks in the street on May 4, 2017 in Beijing, China. Sandstorms are common in northern China during the spring season and are caused when heavy winds from Mongolia in the north brings sand and pollutants that can blanket Chinese cities and cause air quality to deteriorate. (Photo by Kevin Frayer/Getty Images)

Members of the staff wait for the start of the maiden press conference for China's all-girl “boyband” FFC-Acrush in Beijing, China April 28, 2017. Picture taken April, 28, 2017. (Photo by Damir Sagolj/Reuters)

This picture taken on April 12, 2017 shows men carrying bamboo through a forest near Dashan village near the city of Lin'an, Zhejiang Province. Lin'an is in a area of eastern Zhejiang province whose rich bamboo forests are estimated to supply up to two-thirds of China's bamboo shoots, plus a range of other products derived from the fast-growing plant that are produced both for domestic and overseas markets. (Photo by Johannes Eisele/AFP Photo)

Peacocks are seen covered in bags as a protection of their plume during transportation, in Xiangyang, Hubei province, China April 12, 2017. (Photo by Reuters/Stringer)

A girl broadcasts at live streaming talent agency Three Minute TV in Beijing, China on April 12, 2017. Three Minute TV also arranges cosmetic surgery at partner hospitals for its anchors, arranges small bank loans for the surgery, photographs and markets the anchors and helps them find acting opportunities Deng said. (Photo by Damir Sagolj/Reuters)

Stray dogs stand on tombs in Diamond Hill cemetery in Hong Kong, China, 04 April 2017. According to the lunar calendar, the Qingming Festival is observed on 04 April . The Qingming Festival, also known as Tomb-Sweeping Day, is marked by Chinese people by going to the cemetery to cleaning up tombs, bring flowers, and making offerings to their ancestors. (Photo by Jerome Favre/EPA)