Technicians check a CRH high-speed train at Shanghai Hongqiao High-speed train base on December 28, 2011 in Shanghai, China. China's railway stations have started today to sell tickets for the 2012 Spring Festival travel season scheduled to run between January 8th and February 16th, centred around the Chinese New Year which this year falls on January 23rd. (Photo by ChinaFotoPress/Getty Images)

Julian, left, is photographed by his mother with friend Gianluca, right, under water at a public pool in Gelsenkirchen, Germany, on a hot Friday, July 3, 2015. Germany faces a heat wave with temperatures up to 38 degrees Celsius (100 degrees Fahrenheit) at the weekend. (Photo by Martin Meissner/AP Photo)

A cave diver in Anhumas Abyss, Bonito, Brazil. (Photo by Marcio Cabral/Epson International Pano Awards 2018)

A dancer performs during Portuguese designer Teresa Martins for TM Collection during her runway show at the 41st edition of the Portugal Fashion Event in Lisbon, Portugal, 14 October 2017. (Photo by Jose Sena Goulao/EPA/EFE)

Isabella Busse, 6, walks through floodwater near the Seal Beach Pier during a storm in Seal Beach, Calif., Sunday, January 22, 2017. The heavy downpour on Sunday drenched Orange County in one of the heaviest storms of the year. Fast-moving floodwaters swept through California mountain communities and residents fled homes below hillsides scarred by wildfires as the third in the latest series of storms brought a deluge Sunday and warnings about damaging mudslides. (Photo by Ana Venegas/The Orange County Register via AP Photo)

Peacocks are seen covered in bags as a protection of their plume during transportation, in Xiangyang, Hubei province, China April 12, 2017. (Photo by Reuters/Stringer)

A boat sails behind a woman looking through binoculars as she sits on a cliff on a sunny day in Sydney, Australia, May 29, 2016. (Photo by David Gray/Reuters)

“Romantic”. A brown bear in Martinselkonen, Finland. (Photo by Valtteri Mulkahainen/Comedy Wildlife Photography Awards)