A visitor poses for a picture during Sao Paulo Fashion Week in Sao Paulo, Brazil, March 16, 2017. (Photo by Nacho Doce/Reuters)

This undated handout photograph released by Stony Brook University/ Louisiana State University on March 2, 2018, shows an Adélie penguin looking at a drone at breeding colony on Heroina Island, Danger Islands, Antarctica. A thriving “hotspot” of some 1.5 million Adelie penguins has been discovered on the remote Danger Islands in the east Antarctic, surprised scientists announced on March 2, 2018. (Photo by Rachael Herman/AFP Photo/Louisiana State University AND Stony Brook University)

One of the last incoming trains arrives outside the main train station after Deutsche Bahn cancelled all train traffic in Germany due to heavy storms, Frankfurt, Germany, Thursday, January 18, 2018. (Photo by Michael Probst/AP Photo)

A pro-Russian rebel shows his t-shirt depicting Russian President Vladimir Putin at a checkpoint in the village of Chornukhyne near the town of Debaltseve, north-east from Donetsk, March 12, 2015. (Photo by Marko Djurica/Reuters)

An Afghan girl makes a pile of unbaked bricks near the road passing through the Shamali Plains, about 10 kilometers (6 miles), west of Bagram, Afghanistan, Wednesay April 9, 2003. Children assist parents in their job to supplement family income. (Photo by Gurinder Osan/AP Photo)

The front wheels of a tractor lift off the ground as the driver moves a heavy trailer outside Peshawar, Pakistan February 19, 2018. (Photo by Fayaz Aziz/Reuters)

Two white storks stand close to each other on their nest on a tree in Zerbolo, Italy, Thursday, October 26, 2017. (Photo by Antonio Calanni/AP Photo)

People walk past part of an outdoor display as preparations continue for the upcoming pop culture convention Comic Con in San Diego, California, U.S., July 17, 2018. (Photo by Mike Blake/Reuters)