South Korean students pose for a selfie following a traditional coming-of-age ceremony at Namsan hanok village in Seoul on May 15, 2017. The Coming of Age Day is the day to celebrate and encourage the youth who have reached the age of 20, which is considered the beginning of adulthood. (Photo by Ed Jones/AFP Photo)

People watch dragon dance performance in front of a business establishment in celebration of Chinese New Year at Manila's Chinatown district of Binondo, Philippines, Friday, January 31, 2014. (Photo by Bullit Marquez/AP Photo)

A Palestinian female masked militant from the Al-Quds Brigades, the military wing of the Islamic Jihad, takes part in an Islamic Jihad rally in Rafah, southern Gaza Strip, 29 July 2016. (Photo by Mohammed Saber/EPA)

A red fox sits in front of a Eurofighter Typhoon combat jet on the grounds of the 2014 ILA Berlin Air Show, in Selchow near Schoenefeld, Germany, Thursday, May 15, 2014. The International Aviation and Aerospace Exhibition ILA will take place from May 20 until May 25, 2014. (Photo by Patrick Pleul/AP Photo/DPA)

Cowboys Wyatt Williams (R) and David Thompson work to restrain a calf in order to give it medicine near Ignacio, Colorado June 12, 2014. The land where the cattle graze is leased from the Forest Service by third-generation rancher Steve Pargin. Several times a year, he and a crew led by his head cowboy, David Thompson, spend a week or more herding cattle from mountain range to mountain range to prevent them from causing damage to fragile ecosystems by staying in a single area too long. (Photo by Lucas Jackson/Reuters)

A visitor holds an Israeli-made rifle during the 8th International Land and Naval Defense system exhibition, in New Delhi, India, on February 6, 2014. (Photo by Anindito Mukherjee/Reuters)

Three-month old cheetah cubs make their public debut at the Smithsonian National Zoo on July 24, 2012 in Washington, DC. (Photo by T.J. Kirkpatrick)

A young woman holds her smartphone at Red Square with the Kremlin's Spasskaya Tower, right, and St. Basil Cathedral, center, in the background in Moscow, Russia, Monday, July 25, 2016. (Photo by Pavel Golovkin/AP Photo)