An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

Bangladeshi fisherman feed their otters as they catch fish in Narail some 208 kms from Dhaka on March 11, 2014. The fishermen are using a rare technique that relies on coordination between man and trained otters, a centuries-old fishing partnership that has already long died out in other parts of Asia. (Photo by Munir Uz Zaman/AFP Photo)

A vehicle leaves light trails in a long exposure photograph as it drives beneath the 500-metre Aperture Spherical Radio Telescope in Pingtang county, China. Construction on the device began in 2011 and is nearing completion. (Photo by Liu Xu/AP Photo)

A farmer seen harvesting his crops while Mount Sinabung spewing out volcanic ash on July 4, 2017 in North Sumatera, Indonesia. The increased volume of lava dome that reaches one million eight hundred cubic meters, said volcanologist, through radio communications, do not dampen the activities of the people around sinabung, such as farming, harvesting their crops, picking up objects that are still left behind, or just take a picture while walking around near mount Sinabung. (Photo by Sabirin Manurung/Pacific Press/Barcroft Images)

New Orleans police officers try to keep their heads down as they move in on a Black Panther headquarters during an exchange of gunfire in New Orleans on September 15, 1970. The shootout occurred as police moved in to make arrests on Tuesday morning following a series of incidents. (Photo by Jack Thornell/AP Photo)

A man dressed as a devil performs during a Krampus parade in Kaprun, Austria on December 5, 2017. Krampus is a mythical creature that, according to legend, accompanies Saint Nicholas during the festive season. Instead of giving gifts to good children, he punishes the bad ones. (Photo by APA-PictureDesk GmbH/Rex Features/Shutterstock)

Hotel ushers pose for a photo at Tiananmen Square as delegates attend the second plenary session of the National People's Congress (NPC) in Beijing, China, March 9, 2018. The CPPCC is the top advisory body of the Chinese political system and runs alongside the annual plenary meetings of the 13th National People's Congress (NPC), together known as “Lianghui” or “Two Meetings”. (Photo by Jason Lee/Reuters)

In this January 4, 2016 photo, the weapon of a rebel fighter for the 36th Front of the Revolutionary Armed Forces of Colombia, or FARC, hangs from a branch serving as a makeshift clothesline, near a rebel camp, in Antioquia state, in the northwest Andes of Colombia. “We’ll lay aside our weapons, like the accord says, but never hand them over”, says Juan Pablo, a commander of the 36th Front. (Photo by Rodrigo Abd/AP Photo)