In this October 27, 1983 file photo, soldiers brandish captured AK-47 rifles from the windows of a civilian vehicle as they drive near Point Salines Airport in St. George, Grenada. In 1983, U.S. forces invaded the Caribbean island of Grenada after accusing the government of allying itself with Communist Cuba. (Photo by Doug Jennings/AP Photo)

An Afghan boy looks through the scope of a toy gun, as other children ride on swings during the first day of the Muslim holiday of Eid al-Fitr, which marks the end of the holy month of Ramadan, in Kabul, Afghanistan June 25, 2017. (Photo by Omar Sobhani/Reuters)

The finishing touches are made to a new wax figure of Theresa May at Madame Tussauds in London, England on November 7, 2017. (Photo by Victoria Jones/PA Wire)

An injured supporter of Kenyan opposition leader Raila Odinga receives assistance in Nairobi, Kenya on November 17, 2017. Kenyan police have used tear gas and water cannons to disperse supporters of opposition leader Raila Odinga who are trying to gather near the country's main airport and Uhuru park to welcome him back from an overseas trip. (Photo by Baz Ratner/Reuters)

Indian young men wearing traditional folk dance “Bhangra” attire of Punjab, sit on see-saws and sip on soft drinks at a park before their performance during the Khalsa College International Folk Festival 2017 in Amritsar, India, 29 November 2017. The festival is aimed to promote cultural ties between India and participating countries. (Photo by Raminder Pal Singh/EPA/EFE)

A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

An unidentified elderly woman, who was knocked over during the melee after a shot was fired in the direction of President Ford, is comforted by a passerby in San Francisco, September 23, 1975. (Photo by AP Photo)

In this Wednesday, January 3, 2018 photo, yoga instructor Danuta Wolk-Laniewski, demonstrates goat yoga at the Aussakita Acres farm in Manchester, Conn. The farm is partnering with the Hartford Yard Goats, the Double-A affiliate of the Colorado Rockies baseball team, to offer goat yoga at Dunkin Donuts Park, the team's $71 million stadium in Hartford. (Photo by Pat Eaton-Robb/AP Photo)