Guests attend preview event for “Candytopia”, the outrageously interactive candy wonderland, opening in San Francisco, USA on September 6, 2018. (Photo by Kelly Sullivan/Getty Images for Candytopia)

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)

Reveller in costume with a broom jumps during a Zombie Walk event in central Kiev, Ukraine on October 27, 2018, ahead of Halloween celebrations on October 31. (Photo by Anatolii Stepanov/AFP Photo)

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

Central Palo Seco power station of the Puerto Rico Electric Power Authority (PREPA) is seen behind a cemetery, in San Juan, Puerto Rico on January 22, 2018. (Photo by Alvin Baez/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 cow is seen on land that used to be under water, at the Aculeo Lagoon in Paine, Chile, May 14, 2018. (Photo by Matias Delacroix/Reuters)