A Syrian man rides his bicycle past a man selling grains during a halt in fighting on February 29, 2016 in Douma, in the Eastern Ghouta region, east of the capital Damascus. A UN-backed ceasefire deal took hold across parts of Syria, bringing relative calm to areas where the Islamic State group and Al-Qaeda's local affiliate are not present. (Photo by Sameer Al-Doumy/AFP Photo)

A general view of dried-up rivers in the Pilbara region of Western Australia December 2, 2013. Western Australia's Pilbara region, which is the size of Spain, has the world's largest known deposits of iron ore and supplies nearly 45 percent of global trade in the mineral. (Photo by David Gray/Reuters)

Jan Kara (R) and Jan Holan pedal their boat, made with plastic bottles, on the Elbe river near Kostelec nad Labem July 15, 2014. Jan Kara, a 22-year-old student, and Jakub Bures, a 22-year-old car mechanic, built the 10-metre (32.8-feet) long boat from 5000 plastic bottles strapped to a wooden frame. (Photo by David W. Cerny/Reuters)

A baby rhesus macaque (Macaca mulatta) looks up as it plays with a tiger cub at a zoo in Hefei, Anhui province, August 2, 2012. (Photo by Jianan Yu/Reuters)

Super-cell thunderstorms, whirling tornados and lightning bolts illuminating the sky – these photos capture the terrifying brilliance of American storms. (Photo by Brandon Goforth/Solent News & Photo Agency)

Women take a photo in the late afternoon sun during the Coachella Valley Music and Arts Festival on April 17, 2017 in Indio, California. (Photo by Carlo Allegri/Reuters)

A dog walker on Longsands beach before sunrise in Tynemouth, UK on April 1, 2016. (Photo by Owen Humphreys/PA Wire)

The driver of a Maerlitram (fairy tram), dressed as a Santa Claus, walks past a car which crashed into the tram in Zurich, Switzerland December 7, 2017. (Photo by Angelika Gruber/Reuters)