A fisherman boats in Chao Lake where thick cyanobacteria gather on the surface on August 5, 2015 in Chaohu, Anhui Province of China. As high temperature came in summar, part of water in Anhui Province's Chao Lake breeds large tracts of cyanobacteria which not only brought pollution to sense of smell, but also affected people's life. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

An opposition supporter gestures with a knife during clashes with police in Kibera slum in Nairobi, Kenya on October 26, 2017. Kenyans trickled into polling stations today for a repeat election that has polarised the nation, amid sporadic clashes as supporters of opposition leader ignored his call to stay away and tried to block voting. (Photo by Goran Tomasevic/Reuters)

Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)

A picture made available 27 November 2015 shows a handler putting his head between the gaping fangs of a crocodile during a show at the Samutprakarn Crocodile Farm and Zoo, Samutprakarn province, outside Bangkok, Thailand, 26 November 2015. The farm and zoo claims to be the world's largest crocodile farm with more than 80,000 freshwater and marine crocodiles, and offers shows such as crocodile wrestling to attract tourists. (Photo by Diego Azubel/EPA)

An election poster calling for the legalisation of marijuana and featuring internet meme “Grumpy Cat” hangs outside the Pirate Party's campaign headquarters in Berlin on August 16, 2013. The Pirates, who to everyone's surprise were elected into Berlin's regional parliament in September 2011, are trying to capitalise on their recent electoral gains in upcoming parliamentary elections, running on a platform of transparency in government. Germany goes to the polls on September 22, 2013. Placard reads: “Hurry up, my dope is everything”. (Photo by John Macdougall/AFP Photo)

People sit on the top of a truck heavily piled with corn-stalks plies as they head for Mogadishu from Afgooye on October 19, 2016. At least four police officers were killed on October 18 when a suicide bomb attacker rammed an explosives-packed car into a police station before fighters from the Al-Qaeda-linked Shabaab group subsequently stormed the area killing at least 10 people, including soldiers and civilians. (Photo by Mohamed Abdiwahab/AFP Photo)

Syrians gather during an evacuation operation of rebel fighters and their families from rebel-held neighbourhoods on December 15, 2016 in the embattled city of Aleppo. A convoy of ambulances and buses left rebel territory in Aleppo in the first evacuations under a deal for opposition fighters to leave the city after years of fighting. The rebel withdrawal will pave the way for President Bashar al-Assad's forces to reclaim complete control of Syria's second city, handing the regime its biggest victory in more than five years of civil war. (Photo by Karam Al-Masri/AFP Photo)

Party-goers partake in a festival better known as Holi One, during International Workers Day in Johannesburg, South Africa, 01 May 2015. The colour festival promotes togetherness as well as colourness in everday life. May Day is observed worldwide every year on 01 May. (Photo by Kevin Sutherland/EPA)