U.S. Marines, left, and South Korean Marines, wearing blue headbands on their helmets, take positions after landing on the beach during the joint military combined amphibious exercise, called Ssangyong, part of the Key Resolve and Foal Eagle military exercises, in Pohang, South Korea, Saturday, March 12, 2016. North Korea said Saturday its military is ready to pre-emptively attack and “liberate” the South in its latest outburst against the annual joint military drills by the United States and South Korea. (Photo by Kim Jun-bum/Yonhap via AP Photo)

Waves hit the seawall during heavy seas and high winds in Dawlish in south west Britain, February 2, 2017. (Photo by Toby Melville/Reuters)

Flamingoes in Laguna Colorada, Altiplano, Bolivia, South America in 2018. (Photo by Oksana Belikova/Rex Features/Shutterstock)

Teachers carry children away from Briarwood Elementary school after the tornado destroyed the school in south Oklahoma City. (Photo by Paul Hellstern/The Oklahoman)

South American sea lion. Valencia, February 8, 2012. (Photo by Ger Art; Source: Flickr)

A women sits on the south rim of Grand Canyon National Park in northern Arizona, April 12, 2015. (Photo by Jim Urquhart/Reuters)

Children react as they celebrate Guy Fawkes day in Soweto, South Africa, on November 5, 2014. (Photo by Siphiwe Sibeko/Reuters)

Open jaws of a Great White Shark Carcharodon Carcharias, South Africa. (Photo by Stephen Frink Collection/Alamy Stock Photo)