American actress Paris Jackson pulls faces at photographers during the “Melbourne Cup” race day festivities in Melbourne, Australia on November 7, 2017. (Photo by Media-Mode/Splash News and Pictures)

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)

Riot police clash with demonstrators protesting against proposed pension reforms outside the Congress in Buenos Aires on December 18, 2017. Protesters angry at proposed pension and welfare reforms attacked police close to Argentina's congress building in Buenos Aires on Monday, the second protest in a week to turn violent. Activists lobbed stones, bottles and firecrackers at police as huge crowds demonstrated against pension reforms proposed by the center-right government of President Mauricio Macri. (Photo by Eitan Abramovich/AFP Photo)

A sadhu, or a Hindu holy man, blesses a devotee as he smokes marijuana at a transit camp on the way to Gangasagar, in Kolkata, India, Sunday, January 7, 2018. Thousands of Hindu pilgrims are expected to take the annual holy dip at Gangasagar, where the Ganges River reaches the Bay of Bengal, on the auspicious Makar Sankranti festival day that falls on Jan. 14. (Photo by Bikas Das/AP Photo)

Brides display their hands decorated with henna around a bride as she poses for her own photographer during a mass marriage ceremony in which, according to its organizers, 70 Muslim couples took their wedding vows, in Ahmedabad, India, February 11, 2018. (Photo by Amit Dave/Reuters)

Children enjoy a sledge ride past ice swimming fans at the Zalew Zegrzynski lake in Nieporet, Poland, Sunday, February 25, 2018. A cold wave hit Poland with the temperature minus 8 degree Celsius (17.6 Fahrenheit) during the day and dropping to minus 16 degree Celsius (3.2 Fahrenheit) in the night in central Poland. (Photo by Alik Keplicz/AP Photo)

Russian cadets march during the annual cadet schools get-together in Moscow, Russia on March 30, 2018. (Photo by Mladen Antonov/AFP Photo)

Adventurer Sam Cossman movies towards the huge lava lake wearing a custom built industrial proximity heat suit on December 20, 2014 in Ambrym, Vanuatu. (Photo by Conor Toumarkine/Barcroft Media)