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 picture made available on 14 July 2016 shows Greyhound dogs racing at the Wentworth Park Stadium in Sydney, New South Wales (NSW), Australia, 13 July 2016. Greyhound racing has returned to Sydney's Wentworth Park and other NSW tracks for the first time since the state government announced plans to ban it. NSW Premier Mike Baird announced last week plans to shut down the sport in NSW following a Special Commission of Inquiry report that found “chilling” evidence of systemic animal cruelty within the industry. (Photo by David Moir/EPA)

Two race pigs jump over an obstacle during a rural festivity in reference to Maria Ascension in San Bernardino, Switzerland on Monday, August 15 2016. (Photo by Samuel Golay/Keystone/TI-Press via AP Photo)

Andrea Petkovic of Germany in action against Sara Errani of Italy during day one of the Mutua Madrid Open tennis tournament at the Caja Magica on May 3, 2014 in Madrid, Spain. (Photo by Julian Finney/Getty Images)

A zoo performer smiles as he puts his head between the jaws of a crocodile during a performance for tourists at the Sriracha Tiger Zoo, in Chonburi province, east of Bangkok,Thailand, June 7, 2016. (Photo by Chaiwat Subprasom/Reuters)

Children are engulfed by foam during the Bubble Show event in Beijing, China, Sunday, June 26, 2016. Thousands of residents enjoy colored foam churned out by machines along a running track at the event designed for children and parents' interaction. (Photo by Ng Han Guan/AP Photo)

“The Tonight Show” host Jimmy Fallon, center, exits the water during the Chicago Polar Plunge, Sunday, March 2, 2014, in Chicago. Fallon joined Chicago Mayor Rahm Emanuel in the event. (Photo by Andrew A. Nelles/AP Photo)

A worker applies colour to strings which will be used to fly kites, by a roadside in Ahmedabad, India, November 23, 2017. (Photo by Amit Dave/Reuters)