Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)
A brown bear is checked by foreign veterinaries and local staff members at the Four Paws Bear Sanctuary in Pristina, on May 9, 2014. (Photo by Hazir Reka/Reuters)
Miniature spring-wound 35-mm film camera in a modified cigarette pack. The Tessina’s small size and quiet operation provided more options for concealment than most commercially available models. (Photo by Central Intelligence Agency)
This picture taken on July 25, 2014 shows people cooling off in a waterpark in Suining, southwest China's Sichuan province. Meteorological departments issued an orange alert for high temperature as a heat wave embraces Sichuan province, with temperature of most area topped 37, local media reported. (Photo by AFP Photo)
A Selkirk Rex cat is one of more than 400 breeds of cats being presented at the World Cat Federation two-day show in Dortmund, Germany, on April 21, 2013. (Photo by Frank Augstein/Associated Press)