In this May 24, 2018 file photo, rain drops accumulate on a car's windshield as commuters wait at a red light in Havana, Cuba. (Photo by Desmond Boylan/AP Photo)

Mercury and Maia, fueled and overhauled, are waiting in the Tay at Dundee, for favorable weather to start the flight to the Cape, a distance of 6,370 miles. The composite machine moored in the Tay River, at Dundee, on September 23, 1938. (Photo by AP Photo)

Luke Personius, 12, waits for a wave as he surfs before school at sunrise in Hermosa Beach, California April 2, 2015. The group of friends surf at sunrise most mornings, then shower outside and walk to school. (Photo by Lucy Nicholson/Reuters)

A supporter of China's President Xi Jinping waits on the Mall for him to pass during his ceremonial welcome, in London, Britain, October 20, 2015. Xi is on a State visit to Britain. (Photo by Peter Nicholls/Reuters)

Pakistani street performers sit around fire waiting for customers on a chilly evening in Rawalpindi, Pakistan, Wednesday, November 11, 2015. Some parts of Pakistan are facing a harsh winter. (Photo by B. K. Bangash/AP Photo)

Syrian refugees sit behind barbed wire as they wait to cross into Macedonia at the Greek-Macedonian border, near the village of Idomeni, August 21, 2015. (Photo by Yannis Behrakis/Reuters)

Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

Pakistani street performers sit around fire waiting for customers on a chilly evening in Rawalpindi, Pakistan, Wednesday, February 10, 2016. (Photo by B.K. Bangash/AP Photo)