A tourist jumps inside an upside-down house at Fengjing Ancient Town, Jinshan District, south of Shanghai, May 1, 2014. The upside-down house was built as a tourist attraction using everyday household items and furniture. (Photo by Aly Song/Reuters)

A biker passes by a pair of mailboxes in the Capitol Hill neighborhood November 6, 2012 in Denver, Colorado. Colorado is considered by most experts to be one of the key battleground state in this year's presidential election. (Photo by Marc Piscotty/AFP Photo)

Nikolay Skidan, a hunter, carries the skin of a wolf in the village of Khrapkovo, Belarus February 1, 2017. Wolf fur grows thickest in winter, so Belarussian hunter Vladimir Krivenchik only sets his traps once snow is on the ground. He and his wife live on the edge of the Chernobyl exclusion zone – 2,600 square km of land on the Belarus-Ukraine border that was contaminated by a nuclear disaster in 1986. (Photo by Vasily Fedosenko/Reuters)

Students stand on the roof of a wooden boat as haze blankets the Musi River while they travel to school in Palembang, on Indonesia's Sumatra island, September 10, 2015. Indonesia is investigating 10 firms over worsening forest fires that have created a blanket of smog over Southeast Asia, threatening them with sanctions if they are found responsible, a government minister said on Tuesday. The thick haze from Indonesia's Sumatra and Kalimantan islands has forced the repeated cancellation of flights in the area and pushed air quality to unhealthy levels in neighbouring Singapore and Malaysia. (Photo by Reuters/Beawiharta)

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)

A couple shares a light moment in a Mass Transit Railway (MTR) subway train in Hong Kong, China on August 28, 2019. (Photo by Anushree Fadnavis/Reuters)

A medical worker wearing a full protective outfit tests a man for Covid-19 symptoms in a street in Wuhan, China, 01 April 2020. Wuhan, the epicenter of the coronavirus outbreak, partly lifted the lockdown allowing people to enter the city after more than two months. According to Chinese government figures over 2,500 people have died of Covid-19 in Wuhan since the outbreak began. (Photo by Roman Pilipey/EPA/EFE)

Indian Air Force (IAF) cadets march during a graduation parade at the Air Force Academy in Dundigal, on the outskirts of Hyderabad, India, Saturday, June 20, 2020. A total of 123 flight cadets including 19 women officers were commissioned as flying officers on Saturday on successful completion of their training, a press release said. (Photo by Mahesh Kumar A./AP Photo)