Women walk past a pile of rubbish bags on a street during a strike by garbage collectors demanding delayed salaries in Sanaa, Yemen May 8, 2017. (Photo by Khaled Abdullah/Reuters)

A young man weaves palm fronds into the shape of a cross before the start of a Mass to observe Palm Sunday, at the Metropolitan Cathedral, in Managua, Nicaragua, Sunday, March 29, 2015. For Christians, Palm Sunday marks the start of Holy Week ahead of Easter, commemorating Jesus Christ's entrance into Jerusalem, when his followers laid palm branches in his path. (Photo by Esteban Felix/AP Photo)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

Owners and their dogs take part in “HK Doggie Dash 2018”, an event held to raise money for for abandoned and surrendered dogs in Hong Kong on April 15, 2018. Dozens of pugs and dachshunds compensated for their modest speed with peppy spirits at Hong Kong’s inaugural “doggie dash” on April 15 that raised funds and awareness for the city’s abandoned and rescued dogs. (Photo by Isaac Lawrence/AFP Photo)

Actors perform in a scene during the “Dino Safari” show in Tokyo, Japan, 25 April 2018. The Dino Safari show features dinosaurs moving in a realistic way thanks to the Dino-Tronics mechanism that enable the dinosaurs to walk, move their heads and jaws. The event will run from 26 April to 05 May 2018. (Photo by Franck Robichon/EPA/EFE)

A woman affected by tear gas is assisted during a May Day protest against austerity measures, in San Juan, Puerto Rico May 1, 2018. (Photo by Alvin Baez/Reuters)

Aerial photo taken on April 20, 2018 shows the view of advection fog above Qingdao, a coastal city in east China' s Shandong Province. (Photo by Lu Hui/Xinhua News Agency/Eyevine)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)