A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Takahiro Shito, 47, and his wife Sayomi Shito, 46, pray with their children Tomoka, 14, and Kenya 16, and their great uncle Akinori Takahashi, 76, as they pay respects to their daughter Chisato,12, buried in a nearby cemetery, victim of the Okowa Elementary School tragedy, who was killed during last year's tsunami on March 11, 2012 near Ishinomaki, Japan. Teachers at the school weren't trained for tsunami evacuation and didn't to lead the children up the snow covered mountain behind the school after the tsunami warning was sounded. Out of 108 students at the school, 74 died and four remain missing; 10 of the school's 13 teachers were also killed. (Photo by Daniel Berehulak /Getty Images)

A rainbow is seen near a cloud south of Corvallis, Ore., Monday, May 19, 2014. (Photo by Andy Cripe/AP Photo/The Corvallis Gazette-Times)

Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)

“Oak Sunrise” by professional photographer Alan Price has won the International Garden Photographer of the Year, “Celebrating Our Oaks” competition, run in partnership with Action Oak. Action Oak is a campaign to protect the UK’s oak trees from threats including pests and diseases. (Photo by Alan Price/IGOTY)

Women take part in an annual block party known as “Banda do Candinho e Mulatas” (Candinho Band and Mulatto Women), during carnival festivities at Bixiga neighbourhood in Sao Paulo, Brazil February 7, 2018. (Photo by Nacho Doce/Reuters)

An armed forces members patrol during an operation against drug dealers in Vila Kennedy slum in Rio de Janeiro, March 7, 2018. (Photo by Pilar Olivares/Reuters)