A masked reveller poses near Saint Mark's Square during the Venetian Carnival in Venice January 31, 2015. (Photo by Stefano Rellandini/Reuters)

A trader weighs tobacco at a market in el-Fasher, in North Darfur February 5, 2015. Tobacco is one of the North Darfur war zone's main cash crops. (Photo by Mohamed Nureldin Abdallah/Reuters)

The pit lane is reflected in the visor of a Mercedes Formula One pit crew member during the second practice session of the Australian F1 Grand Prix at the Albert Park circuit in Melbourne March 13, 2015. REUTERS/Brandon Malone

A Ukrainian serviceman who fought in Debaltseve is seen near Artemivsk February 19, 2015. Fighting raged in eastern Ukraine on Thursday despite European efforts to resurrect a still-born ceasefire, a day after pro-Russian separatists who spurned the truce forced thousands of government troops out of a strategic town. (Photo by Gleb Garanich/Reuters)

A participant poses backstage before a drag queen competition during carnival festivities in Las Palmas on the Spanish Canary Island of Gran Canaria February 20, 2015. (Photo by Borja Suarez/Reuters)

A participant falls on vintage skis during a traditional historical ski race in the northern Bohemian town of Smrzovka February 21, 2015. (Photo by David W. Cerny/Reuters)

Vickie Leuenberger (L) practices with a mermaid tail with AquaMermaid founder Marielle Chartier Henault in a pool in Montreal, February 19, 2015. The school teaches kids and adults how to swim wearing mermaid tails, and offers mermaid-themed parties. (Photo by Christinne Muschi/Reuters)

A woman in costume checks her phone at the Star Wars Celebration convention in Anaheim, California, April 16, 2015. The Star Wars Celebration runs through April 19 at the Anaheim Convention Center. (Photo by David McNew/Reuters)