A colorful sky at sunset over the snowy mountains in Immenstadt, Bavaria, Germany, 20 November 2014. Cloudy weather is forecast in the region on 21 November. (Photo by Karl-Josef Hildenbrand/EPA)

Aleksandra Krunic, of Serbia, drops to the court after defeating Petra Kvitova, of the Czech Republic, during the third round of the 2014 U.S. Open tennis tournament, Saturday, August 30, 2014, in New York. (Photo by Kathy Willens/AP Photo)

American actress Nicola Peltz poses on the red carpet as she arrives for the world premiere of the movie “Transformers 4: Age of Extinction” in Hong Kong Thursday, June 19, 2014. The latest installment in the blockbuster series of “Transformers” films is making its world premier not in the usual entertainment hubs of Los Angeles or New York but in the wealthy Chinese metropolis of Hong Kong, the latest sign of Hollywood's increasing focus on China's booming film market. (Photo by Kin Cheung/AP Photo)

A vendor prepares paan, a betel nut-based chewable stimulant at a flower market in Kolkata, India, January 18, 2016. (Photo by Rupak De Chowdhuri/Reuters)

At a beauty contest to select the nation's Queen of Height during the first national convention of Tall People's Clubs in New York on July 29, 1949, little Charlie Young, only three feet, eleven inches tall, acting as judge, had a tough time making up his mind for the choice. The national minimum height requirement for women members is 5 feet 10 inches, and for men, 6 feet. (Photo by Robert Kradin/AP Photo)

A man in “Red Army” garb hits the pavement during a simulated attack during a re-staging of part of the Long March in Jinggangshan September 14, 2017. The scene brings alive an extraordinary chapter in China's history that established the supremacy of Chairman Mao Zedong and the Communist Party. Deep in the mountains of Jinggangshan in the southeastern province of Jiangxi, a classroom of bank tellers participates in an ideological boot camp that plays into Chinese President Xi Jinping's drive to further consolidate his grip on power. (Photo by Thomas Peter/Reuters)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

A housewife whose family lives in a shanty cooks beside a road in Manila, Philippines May 25, 2016. (Photo by Erik De Castro/Reuters)