Artists perform during the opening show directed by German director Volker Hesse, on the opening day of the Gotthard rail tunnel, at the fairground Rynaecht at the northern portal in Erstfeld, Switzerland, Wednesday, June 1, 2016. The construction of the 57 kilometer long tunnel began in 1999, the breakthrough was in 2010. After the official opening on June 1, the commercial operation will start in December 2016. (Photo by Ruben Sprich\Pool Photo via AP Photo)

Cars drive under a rainbow near Bad Langensalza, Germany, Wednesday, November 2, 2016. (Photo by Jens Meyer/AP Photo)

Iranian skiers rest at the Dizin ski resort, northwest of Tehran January 15, 2016. (Photo by Raheb Homavandi/Reuters/TIMA)

A masked reveller poses in San Marco Piazza during the Venice Carnival, January 30, 2016. (Photo by Alessandro Bianchi/Reuters)

A family dressed in traditional chinese clothes celebrates the Chinese New Year in Chinatown in Bangkok, Thailand February 8, 2016. (Photo by Jorge Silva/Reuters)

A man rides a motorcycle along a street in the snow in Altay, Xinjiang Uighur Autonomous region, February 9, 2016. (Photo by Reuters/Stringer)

Clouds gather as walkers pause atop a ridge in Mountain View, California January 7, 2016. (Photo by Noah Berger/Reuters)

Farmers work on a farm near a construction site of new residential buildings in Shanghai, China, February 20, 2016. (Photo by Aly Song/Reuters)