Racegoers during Ladies Day at the Grand National Festival at Aintree Racecourse on April 13, 2018 in Liverpool, England. (Photo by Mercury Press)

A Grevy’s zebra gets itself noticed at ZSL Whipsnade Zoo in Whipsnade, England on April 20, 2018. (Photo by Tony Margiocchi/Barcroft Media)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

In this photograph taken on April 28, 2018, Afghan children work at a coal yard on the outskirts of Jalalabad, Afghanistan. (Photo by Noorullah Shirzada/AFP Photo)

A soldier walks on the bank of the river in central Pyongyang, North Korea on April 16, 2017. (Photo by Damir Sagolj/Reuters)

A student takes part in Tamil New Year and Vishu celebrations in Chennai on April 13, 2022. (Photo by Arun Sankar/AFP Photo)

A Thai and foreign revelers battle with water guns during the annual Songkran celebration at Khaosan Road, a tourist spot in Bangkok, Thailand, 12 April 2017. The four southeast Asian nations of Myanmar, Thailand, Cambodia and Laos started the Buddhist new year, known as Thingyan in Myanmar and Songkran in Thailand, on April 13. (Photo by Rungroj Yongrit/EPA)

A Nepalese vetinary and technical team release a rhino after it is relocated in Chitwan National Park some of 250 Kilometer South of Kathmandu on April 4, 2017. Conservationists on April 3 captured a rare one-horned rhinoceros in Nepal as part of an attempt to increase the number of the vulnerable animals, which are prized by wildlife poachers. Five rhinos – one male and four female – will be released into a national park in Nepal's far west over the coming week in the hope of establishing a new breeding group. (Photo by Prakash Mathema/AFP Photo)