People walk on a sightseeing platform in Zhangjiajie, Hunan Province, China, August 1, 2016. China has opened a 100-metre-long glass skywalk stretching around a cliff on the side of the Tianmen Mountain. The skywalk provides a view of a 300-metre drop and overlooks Tongtian Avenue, a mountain road with 99 turns that snakes up the mountain. When translated in English, it means “Avenue to the Sky”. (Photo by Reuters/Stringer)

Pilots plan a flight manoeuvre with model aircraft at a military air base in Vasylkiv, Ukraine, August 3, 2016. (Photo by Gleb Garanich/Reuters)

A woman uses a tree branch to fight a fire on the road leading to the village of Parada, near Mortagua, northern Portugal, Thursday, August 11 2016. Firefighters in Portugal are battling multiple blazes fed by brush in a hot, dry summer for a sixth straight day. Major fires have also been raging in northwestern Spain and southern France. (Photo by Sergio Azenha/AP Photo)

Indian policewomen perform a stunt on their motorbikes during the full-dress rehearsal ahead of India's Independence Day celebrations in Srinagar, August 13, 2016. (Photo by Danish Ismail/Reuters)

A student participates in celebrations ahead of the Janmashtami festival, which marks the birth anniversary of Lord Krishna in Mumbai, India, August 23, 2016. (Photo by Danish Siddiqui/Reuters)

A solders in ceremonial attire sweats as he waits outside Suddhaisavarya Prasad Hall, in which Thailand's King Maha Vajiralongkorn scheduled to grant a public audience in Bangkok, Thailand, Monday, May 6, 2019. King Maha Vajiralongkorn was officially crowned amid the splendour of the country's Grand Palace, taking the central role in an elaborate centuries-old royal ceremony that was last held almost seven decades ago. (Photo by Gemunu Amarasinghe/AP Photo)

This picture taken on June 1, 2019 shows Alex Gao trying to balance a book on his head during an etiquette and manners class in central Shanghai. Against a soundtrack of classical music, children learn social skills, dining manners and deportment in the class, which costs $390 for four hours of practical instruction per student. (Photo by Hector Retamal/AFP Photo)

This photo provided by NASA astronaut Christina Koch shows the launch of a Russian Soyuz rocket, as seen from the International Space Station on Wednesday, September 25, 2019. (Photo by Christina Koch/NASA via AP Photo)