A performer takes part in the annual street parade, which is part of the Carnival of Cultures celebrating the multi-ethnic diversity of the city, in Berlin, Germany on May 20, 2018. (Photo by Hannibal Hanschke/Reuters)

An air raid drill at Seattle College caught students William Bates, left, and Edna Mae Farrell, right, while they were eating their lunch in the school café, but they simply took shelter under the table and continued eating in Seattle, Washington, March 17, 1942. Air raid wardens said 350 students left their classrooms and assembled in shelters within one minute in first at the college. (Photo by AP Photo)

U.S. first lady Melania Trump steps out of her motorcade vehicle as she departs Washington for a tour of several African countries from Joint Base Andrews, Maryland, U.S., October 1, 2018. (Photo by Carlo Allegri/Reuters)

An Afghan woman walks with a child in the old city of Herat province, Afghanistan on October 15, 2018. (Photo by Mohammad Ismail/Reuters)

A street food vendor waits for customers on a footpath in New Delhi, India, November 27, 2018. (Photo by Anushree Fadnavis/Reuters)

Ayah, 37, weeps as she is embraced by a police officer during a demonstration against the Danish face veil ban in Copenhagen, Denmark, August 1, 2018. (Photo by Andrew Kelly/Reuters)

A woman yawns as she sits outside a hospital on a cold winter morning in Srinagar January 3, 2019. (Photo by Danish Ismail/Reuters)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)