Large trumpet vines spread across electrical lines next to a highway in Kinston, N.C., on June 23, 2014. (Photo by Janet S. Carter/Kinston Free Press via AP Photo)

The US Navy Blue Angels numbers 5 and 6 fly below Sean Tucker (above) as he pilots the Oracle Challenger III over San Francisco, California as part of a practice run for Fleet Week on October 6, 2016. (Photo by Josh Edelson/AFP Photo)

An Afghan woman fills containers with water near her temporary shelter at an internally displaced person's (IDP) camp on the outskirts of Herat, Afghanistan, January 21, 2015. Dozens of families are living in temporary shelters even in harsh winters and most depend on aid distributions by the United Nations High Commissioner for Refugees (UNHCR). (Photo by Jalil Rezayee/EPA)

A Sri Lankan elephant, accompanied by his mahout, browse through a roadside fruit stall in Colombo on January 19, 2015. The Sri Lankan elephant is listed as endangered by the International Union for Conservation of Nature (IUCN) as the population has declined by at least 50 percent over the last three generations, with the species threatened by habitat loss, degradation and fragmentation. (Photo by Lakruwan Wanniarachchi/AFP Photo)

Protesters wear masks, the left in the colors of the Kenyan national flag, as they join others carrying mock coffins and red-painted crosses, symbolizing the blood of the 28 non-Muslims singled out and killed in the recent attack on a bus in Mandera by Somali militant group al-Shabab, outside government offices in downtown Nairobi, Kenya Tuesday, November 25, 2014. (Photo by Ben Curtis/AP Photo)

Serena Williams of the U.S. serves during her first round match against Italy's Camila Giorgi at the Australian Open tennis tournament at Melbourne Park, Australia, January 18, 2016. (Photo by Jason O'Brien/Reuters)

A worker loads palm fruit at a palm oil plantation in North Mamuju regency, West Sulawesi province, Indonesia March 10, 2016 in this photo taken by Antara Foto. (Photo by Sahrul Manda Tikupadang/Reuters/Antara Foto)

Iraqi pro-government forces fire an anti-tank cannon near al-Sejar village, north-east of Fallujah, on May 25, 2016, as they take part in a major assault to retake the city from the Islamic State (IS) group. Iraqi forces, consisting of special forces, soldiers, police, paramilitary-fighters and pro-government tribesmen, launched a major assault to retake Fallujah, the scene of deadly battles during the US occupation and one of the toughest targets yet in Baghdad's war on the Islamic State group. (Photo by Ahmad Al-Rubaye/AFP Photo)