Tourists play at a beach covered by a thick layer of green algae on July 3, 2013 in Qingdao, China. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit the Qingdao coast in recent days. More than 20,000 tons of such seaweed has been removed from the city's beaches. (Photo by China Foto Press)

Seven-year-old Dihan Awallidan from Garut, West Java, is not like other boys his age. While most children crave chocolate and candy, Dihan is addicted to cigarettes. The second-grader picked up the habit at the age of 3 and now smokes up to three packs a day, using the pocket money he gets from his enabling parents to feed his addiction. (Photo by Rezza Estily/JG Photo)

Soldiers stop to buy goods at the main market of Diffa, Niger, March 23, 2015. Diffa is where Nigerien and Chadian troops fighting insurgent group Boko Haram are based at. (Photo by Joe Penney/Reuters)

A visitor kneels down nex to an iCub robot made by the Italian Institute of Technology at the scientists congress IROS 2015 in Hamburg, Germany October 2, 2015. The robot congress is organized by TAMS group (Technical Aspects of Multimodal Systems) of Hamburg's university. (Photo by Fabian Bimmer/Reuters)

A man steers with his legs while riding a motorcycle on a road in Vietnam's northern Hoa Binh province, outside Hanoi, October 15, 2015. (Photo by Reuters/Kham)

Gurung girls wearing traditional costumes dance while taking part in a New Year parade in Kathmandu, Nepal December 30, 2015. Members of the Gurung community in Nepal celebrate their Tamu Lhosar or Losar (New Year) with a feast and various cultural programs to usher in the year of the Monkey. (Photo by Navesh Chitrakar/Reuters)

Just Dance 2017 performance at Ubisoft E3 2016 – Day 2 at the Los Angeles Convention Center on Tuesday, June 14, 2016, in Los Angeles. (Photo by Dan Steinberg/Invision for Ubisoft/AP Images)

Women perform yoga on a dried river bank in Yunyang county, Chongqing Municipality, August 21, 2016. (Photo by Reuters/China Daily)