A man walks through the morning mist in a park in Rozzano, near Milan, northern Italy, Thursday, December 17, 2015. (Photo by Antonio Calanni/AP Photo)

Dogs, Pretty, Llilly, and Rocky wait for their turn to be examined by veterinarians during a community campaign for the sterilisation and deworming of dogs and cats in Havana, Cuba February 25, 2016. (Photo by Reuters/Stringer)

Military enthusiasts take part in a re-enactment of the World War II battle of Stalingrad at the “Stalin Line” memorial, near the village of Goroshki, Belarus, February 27, 2016. (Photo by Vasily Fedosenko/Reuters)

Participants run at the “Half-Naked Marathon” at Olympic Forest park in Beijing, China, February 28, 2016. This annual running event which requires participants to run half-naked, was organized to promote environmentally friendly lifestyles. (Photo by Kim Kyung-Hoon/Reuters)

A woman collects water from a stream outside the village of Tsemera in Ethiopia's northern Amhara region, February 13, 2016. (Photo by Katy Migiro/Reuters)

“Festive preparation”. Baghnapara, Bardhaman, West Bengal, India. Two girls prepare for the Gajan festival. They will perform a play based on Indian mythology. (Photo by Krishnasis Ghosh)

A tank crew competes in an individual race at a regional stage of the 2016 Tank Biathlon Competition at the Anastasyevsky training ground, March 1, 2016, Khabarovsk Territory, Russia. (Photo by Yuri Smityuk/TASS/Newscom)

The Proton rocket, that will launch the ExoMars 2016 spacecraft to Mars, is transfered to the launchpad at the Baikonur cosmodrome, Kazakhstan, in this handout photo released by European Space Agency (ESA) on March 11, 2016. (Photo by Stephane Corvaja/Reuters/ESA)