A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

A visitor poses for a photograph in front of a 3D painting depicting a Japanese Imperial army soldier at a 3D art gallery in Beijing January 16, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A woman dressed up as a zombie participates in a zombie walk in Stockholm, Sweden on August 19, 2017. (Photo by Jonathan Nackstrand/AFP Photo)

One-year-old female giant panda cub Nuan Nuan reacts inside her enclosure during joint birthday celebrations for the panda and its ten-year-old mother Liang Liang at the National Zoo in Kuala Lumpur on August 23, 2016. Giant pandas Liang Liang, aged 10, and her Malaysian-born cub Nuan Nuan, 1, were born on August 23, 2006 and August 18, 2015 respectivetly. (Photo by Mohd Rasfan/AFP Photo)

Participants wearing masks during a hazy day at the Beijing International Marathon in front of Tiananmen Square, in Beijing, October 19, 2014. (Photo by Reuters/Stringer)

Cosplayers dressed as Star Wars characters Chewbacca (R) and Darth Vader talk at a Star Wars Day fan event in Tokyo May 4, 2015. Star Wars fans celebrate May 4 as Star Wars Day, a pun that comes from an iconic quote in the movie, “May the Force be with you”. (Photo by Toru Hanai/Reuters)

Policemen look at a wax figure of Rowan Atkinson, dressed as his popular television character Mr. Bean, on display outside a wax figure museum in Guangzhou, Guangdong province, August 24, 2014. (Photo by Alex Lee/Reuters)

Secondary school students perform a barefoot “pilgrimage of suffering” to support the Occupy Central civil disobedience movement at the Admiralty protest site in Hong Kong November 30, 2014. It has been two months since police first fired tear gas to disperse demonstrators from the main protest site in the Admiralty district next to government offices in the heart of the Asian financial centre. (Photo by Bobby Yip/Reuters)