World Champion Trials bike rider Jack Field of Australia poses after performing the highest backflip on a motorcycle ever recorded as he flips his motorbike upside down on the roof of Melbourne's Eureka Tower (297.3 metres) during a AUS-X Open media opportunity at Eureka Tower on May 22, 2019 in Melbourne, Australia. The largest international Supercross and action sports event in the world outside of the USA, the AUS-X Open will be held at Melbourne's Marvel Stadium on November 30 2019. (Photo by Scott Barbour/Getty Images)

Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

A Chinese ethnic Lisu honey hunter holds a large piece of wax from a hive while gathering wild cliff honey in a gorge on May 10, 2019 near Mangshi, in Dehong prefecture, Yunnan province China. (Photo by Kevin Frayer/Getty Images)

A Sudanese man plays a local music instrument ahead of a meeting with Mohamed Hamdan Dagalo, also known as Himediti, deputy head of Sudan's ruling Transitional Military Council (TMC) and commander of the Rapid Support Forces (RSF) paramilitaries, in the capital Khartoum on June 18, 2019. (Photo by AFP Photo/Stringer)

This picture taken on May 24, 2019 shows Mariam the dugong as she is cared for by park officials and veterinarians from the Phuket Marine Biological Centre on Libong island, Trang province in southern Thailand. An orphaned baby dugong rescued off a beach in Krabi province is Thailand's newest star, capturing the hearts of millions on social media and igniting an awarness for ocean conservation as authorities hand-raise the young mammal. (Photo by Sirachai Sirachai Arunrugstichai/AFP Photo)

A child covered in mud on Lake Chokrak near the village of Kurortnoye, Leninsky District of Crimea in Russia on July 4, 2019. (Photo by Sergei Malgavko/TASS)

Firefighters extinguish a fire in Kampar, Riau province on Indonesia's Sumatra island on August 13, 2019. Indonesian authorities are deploying thousands of extra personnel to prevent a repeat of the 2015 fires, which were the worst for two decades and choked the region in haze for weeks. (Photo by Wahyudi/AFP Photo)

A woman instructs a boy on how to pose for pictures in front of a mural depicting Soviet pilot Valery Chkalov – who took a non-stop flight over the Arctic and landed in the US state of Washington in 1937 – at Chkalovskaya metro station in Moscow on August 14, 2019. (Photo by Yuri Kadobnov/AFP Photo)