Participants hang from ropes as they learn how to use safety gears at an experience centre for construction safety training in Beijing, September 5, 2014. The centre which opened in June 2014 was established to educate workers about construction safety. According to the centre, about 1,000 construction workers undergo 3-hour classes which comprises of 33 modules every month. (Photo by Kim Kyung-Hoon/Reuters)

A P-51 Mustang named “Charlotte's Chariot” from the Southern Heritage Air Foundation flies past a cloud of smoke and fire from a nearby battle reenactment during the Wings Over Houston Airshow in Houston, on Saturday, November 1, 2014. Battle reenactments are part of the yearly show held at Ellington Airport. (Photo by Kar Hlava/AP Photo/Bay Area Citizen)

A large balloon of a face of “ojisan”, a middle aged man, floats in the sky above the grounds of Nishiki elementary school in Utsunomiya in Tochigi prefecture, 100km north of Tokyo on December 21, 2014. Members of art group “Me”, meaning “eye” in Japanese and the Utsunomiya Museum of Art launched an art installation “The Day an Ojisan's Face Floated in the Sky”, a 15-meter by 10-meter face balloon of the depicted man, who was auditioned in the city, looking down on his home town from the sky. (Photo by Yoshikazu Tsuno/AFP Photo)

A young woman wearing no trousers hits the ski slopes at a ski resort in Xuzhou, in east China's Jiangsu province on January 13, 2015 in a promotional effort to equal “No Pants Subway Ride”, which was marked on January 11 this year. The promotional “No Pants Subway Ride” stunt on January 11 was held as commuters in some 60 cities around the world braved public transportation in their undies, which has gone global since its first staging by US group Improv Everywhere in New York in 2002. (Photo by AFP Photo)

Su Daocheng rides his home-made mechanical horse vehicle on a street in Shiyan, Hubei province January 18, 2015. Su spent 2 months making this 1.5 metre high and 2 metre long horse, which weighed 250 kilograms with 4 legs and 2 supportive wheels, local media reported. (Photo by Reuters/Stringer)

Members of the Al-Baraa bin Malek batallion, part of the Free Syria Army's Al-Fatah brigade, duck to the ground as they pull a man (R) who was shot by a sniper twice in the Bustan al-Basha district of the northern city of Aleppo on October 20, 2012. (Photo by Javier Manzano/AFP Photo)

A woman sells Cuban Communist Party (PCC) official newspaper Granma with a picture of former Cuba's President Fidel Castro at the front page, at the main touristic road in Havana, Cuba, September 14, 2016. (Photo by Alexandre Meneghini/Reuters)