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)

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)

Visitors pose for pictures under blooming cherry blossoms at a botanical garden in Nanjing, capital of China’s eastern Jiangsu province on March 15, 2019. (Photo by Reuters/China Stringer Network)

People walk in the rainstorm as typhoon Lekima approaches in Shanghai, China on August 10, 2019. The death toll from Typhoon Lekima rose to 49 on August 13 and 21 were still missing after the monster storm wreaked havoc on China's eastern coast, causing huge damage with strong gales and torrential rain. (Photo by Aly Song/Reuters)

This picture taken on June 25, 2019 shows couples wait for their turn for their pre-wedding photo shoot at the Love Story in Rome Studio in Beijing. Increasingly elaborate pre-wedding photos are a booming industry in China, as young couples spend time and cash lining up glamorous photo shoots to display on their big day. (Photo by Fred Dufour/AFP Photo)

An elderly man uses a fan to shade himself from the sun as he walks in a public park in Beijing, Tuesday, June 7, 2016. Thursday marks the Duanwu Festival, a public holiday in China celebrated with outdoor activities including dragon boat races. (Photo by Mark Schiefelbein/AP Photo)

A man sits on top of a car as he is stranded on a flooded street in Tianjin, China, July 20, 2016. (Photo by Reuters/Stringer)

Young dancers perform at a preview show for the Chinese Lantern Festival which falls on February 6 and traditionally marks the end of the Lunar New Year celebrations on February 3, 2012 in Beijing, China.The Lantern Festival also known as the Yuanxiao Festival or Shangyuan Festival in China.(Photo by Lintao Zhang/Getty Images)