Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

A sunflower “smiles” in a field in Tokyo on August 7, 2014. Some 20,000 sunflowers were enjoyed by visitors to the area this week. (Photo by Yoshikazu Tsuno/AFP Photo)

Vehicle lights illuminate a street after a massive blackout, in San Juan, Puerto Rico, Thursday, September 22, 2016. Puerto Ricans faced another night of darkness Thursday as crews slowly restored electricity a day after a fire at a power plant caused the aging utility grid to fail and blacked out the entire island. (Photo by Carlos Giusti/AP Photo)

Students are seen on a pickup truck at the agricultural road which leads to the capital city of Cairo, Egypt, October 13, 2016. (Photo by Amr Abdallah Dalsh/Reuters)

A newly born Sitatunga calf seen at ZSL Whipsnade Zoo on November 24, 2016 in Whipsnade, England. The swamp-dwelling species, also known as a marshbuck, is Africa's only true amphibious antelope. It was snuggled up in the leaves and almost perfectly camouflaged as it mother tended it. (Photo by Tony Margiocchi/Barcroft Images)

Rusting old petrol pumps outside a long-closed rural village petrol station are seen on a minor road near Trowbridge, Britain, October 21, 2016. From art deco apartments in Sussex to a trendy burger bar in London, some of England's former petrol stations are enjoying a new lease of life following creative makeovers. The overhaul opportunities have been created as more than 20,000 stations closed in the United Kingdom over the past 40 years, according to the U.K.'s Petroleum Industry Association (PIC). (Photo by Toby Melville/Reuters)

Fighters from the Democratic Forces of Syria prepare their weapons in the southwestern countryside of Hasaka, Syria February 17, 2016. Picture taken February 17, 2016. (Photo by Rodi Said/Reuters)

A bakery worker rides a bicycle as he carries fresh bread on his head in Cairo, Egypt, February 9, 2016. (Photo by Asmaa Waguih/Reuters)