People walk past a sculpture entitled “Reunion” by artist Sam Jinks at a preview of the Melbourne Art Fair in Melbourne on August 1, 2018. The sculpture is made of silicone, pigment, resin and human hair. (Photo by William West/AFP Photo)

A dog jumps into a swimming pool to retrieve a ball during the Chatsworth House Country Fair near Edensor, Britain on August 31, 2018. (Photo by Darren Staples/Reuters)

Two hippopotamus are fed with pumpkins at the Hanoi Zoo, in Hanoi, Vietnam, 25 October 2018. The zoo has been the home for more than 800 animals of over 90 different species, including three hippopotamus, since it was built in 1976. (Photo by Luong Thai Linh/EPA/EFE)

Prayer flags fly at Namgyal Tsemo Monastery above the town of Leh in Ladakh, India September 24, 2016. High in the Indian Himalayas, young novice monks in maroon robes take their lessons inside the 15th-century Thiksey monastery. (Photo by Cathal McNaughton/Reuters)

Kuwaitis play in front of kites at for Kuwaiti al-Farsi Kites team, Kuwaiti desert, 50 kilometers south of Kuwait City, 06 January 2017 (Issued 07 January 2017). (Photo by Raed Qutena/EPA)

Models sit backstage during Dakar Fashion Week in the Senegalese capital, Friday June 30, 2017. The continent's fashion scene has grown steadily over the past two decades with Sub-Saharan Africa's apparel and footwear market now worth $31 billion, according to data by Euromonitor. (Photo by Finbarr O'Reilly/AP Photo)

Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

Six year old Gillian Smith preparing for the All England Stage Dancing Competition where she has previously won five certificates and a silver medal in the under sevens category. (Photo by Terry Fincher/Keystone/Getty Images). 5th July 1957