A man walks on the road between Nouahibou and Nouakchott, where three Spanish aid workers were abducted in Mauritania, December 3, 2009. (Photo by Rafael Marchante/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)

Francisco da Silva Vale, 61, cools off fish with ice produced on solar-powered ice machines at Vila Nova do Amana community in the Sustainable Development Reserve, in Amazonas state, Brazil, September 23, 2015. Three solar-powered machines, are producing about ninety kilos of ice per day, in a region with poor access to electric energy, which used to be produced only with diesel oil, in the Amazon rain forest. (Photo by Bruno Kelly/Reuters)

A U.S. Army B-24 Liberator Bomber is hailed by a ground crewman as it takes off over a line of shark- nosed fighter planes at an advanced base in China on a mission on October 10, 1943, to bomb Japanese installations. (Photo by AP Photo)

Labourers load a three-wheeled vehicle onto the back of a van at the Mercato market in Addis Ababa October 9, 2015. Addis Ababa's “Mercato” – Italian for “market” – is reputedly the biggest open-air market in Africa, lying in the west of the capital. (Photo by Tiksa Negeri/Reuters)

Tourists walk above a tea plantation in Enshi, Hubei province, December 27, 2015. (Photo by Reuters/Stringer)

Indonesian motorists push their motorbikes as they wade through a flooded street outside the presidential palace in Jakarta, Indonesia, 09 February 2015. Incessant rain overnight triggered widespread flooding in the Indonesian capital Jakarta, bringing traffic to a standstill. The city hall in central Jakarta and the front lawn of the presidential palace were inundated in up to 20 centimetres of water, television pictures showed, after heavy rain. (Photo by Mast Irham/EPA)

A farmer harvests tobacco leaves at a plantation in the valley of Vinales, in the western Cuban province of Pinar del Rio, January 27, 2015. (Photo by Pilar Olivares/Reuters)