“Be prepared” is the motto of petite Doris Sherrell, vocalist and dancer with “Blackouts of 1942”. In the event of a bombing, the young lady had her social security number tattooed on one leg by artist Jack Julian, and address placed on the other limb for means of identification in Los Angeles, September 29, 1942. (Photo by AP Photo)

Indian Air Force personnel parade during the 85th Air Force Day celebrations at Hindon Air Force base in Ghaziabad on October 8, 2017. (Photo by AFP Photo/Stringer)

A man looks at kebabs cooking on the street side in Rawalpindi, Pakistan October 2, 2017. (Photo by Caren Firouz/Reuters)

A demonstrator catches fire during clashes with riot police within a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela's angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro's plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Ronaldo Schemidt/AFP Photo)

Revellers chat on Havana's Malecon seafront before performing at a carnival parade, Cuba, August 12, 2016. (Photo by Alexandre Meneghini/Reuters)

In this September 1, 2016 photo, 90-year-old street vendor Antonio Bauza waits for tourists to sell his bananas, next to the village church in Remedios, Cuba. With the arrival of the first commercial flights from the U.S. to Cuba in more than 50 years, the Cuban government is welcoming the wave of new visitors and struggling to update infrastructure that's already overwhelmed. (Photo by Ramon Espinosa/AP Photo)

A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

A photograph of Cuba's former President Fidel Castro decorates a wall inside a state-run market in Havana, March 8, 2016. (Photo by Alexandre Meneghini/Reuters)