Jan Kara (R) and Jan Holan pedal their boat, made with plastic bottles, on the Elbe river near Kostelec nad Labem July 15, 2014. Jan Kara, a 22-year-old student, and Jakub Bures, a 22-year-old car mechanic, built the 10-metre (32.8-feet) long boat from 5000 plastic bottles strapped to a wooden frame. (Photo by David W. Cerny/Reuters)

Starting on Monday, August 12, Perseid meteors will streak across the summer sky for a couple of nights, offering casual stargazers and serious nighttime photographers a chance to capture a glimpse of the annual meteor shower. Photo: Photographer David Kingham created this composite image from 23 photos on August 12, 2012. (Photo by David Kingham)

South Korea's Shim Sukhee falls in the women's 1,500m short track speed skating heat event during the Pyeongchang 2018 Winter Olympic Games, at the Gangneung Ice Arena in Gangneung on February 17, 2018. (Photo by Mladen Antonov/AFP Photo)

This picture taken on May 31, 2018 shows a villager walking between abandoned houses covered with overgrown vegetation in Houtouwan on Shengshan island, China' s eastern Zhejiang province. Houtouwan was a thriving fishing community of sturdy brick homes that climb up the steeply hilled island of Shenghshan, but is now abandoned, with entire houses completely overgrown as if vacuum- sealed in a lush layer of green. (Photo by Johannes Eisele/AFP Photo)

Zhao Deli waves as he pilots his self-made “flying scooter” in Dongguan, Guangdong Province, China, 12 August 2018 (issued 16 August 2018). Inspired by a cartoon he watched as a child, Zhao Deli sold off his apartment in pursuit of his dream of building a flying scooter. (Photo by Aleksandar Plavevski/EPA/EFE)

South Korean girl group KARA arrive during the 21st High1 Seoul Music Awards at Olympic gymnasium on January 19, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

New York City policemen tangled with demonstrators at a subway station on the opening day of the New York World's Fair, April 22, 1964. Youths attempted to stall the train, which was headed from the city to the fairgrounds, as a form of protest on behalf of civil rights for blacks. (Photo by Charles Gorry/AP Photo)

A guide dangles a live chicken in front of a crocodile in the village of Bazoule, Burkina Faso, December 4, 2015. The villagers believe the crocodiles that live there are sacred. (Photo by Joe Penney/Reuters)