Anti-frost candles burn in apricot plantations to protect flowering buds and blossoms from frost in the midst of the Swiss Alps, in Saxon, Canton of Valais, Switzerland, 05 April 2019. With an unusually low temperature forecast for the season, fruit growers try to protect their buds from frost damage with two different means, icy water or large candles. (Photo by Valentin Flauraud/EPA/EFE)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)

Russian servicemen stand next to a Russian Yars RS-24 intercontinental ballistic missile system before a rehearsal for the Victory Day parade, with the Moscow International Business Center also known as “Moskva-City” seen in the background, at a range in Moscow, Russia, May 5, 2016. (Photo by Maxim Shemetov/Reuters)

A hooded protester throws a petrol bomb to riot policemen during clashes, following a rally marking the 43rd anniversary of a 1973 student uprising against the military dictatorship that was ruling Greece, in Athens, Greece, November 17, 2016. (Photo by Yannis Behrakis/Reuters)

This photo taken on April 7, 2018 shows Rohingya refugee attending a demonstration of elephant resistance arranged by the UNHCR and IUCN at the Kutupalong refugee camp in Ukhia, Bangladesh. The purpose of the training day is sobering – a dozen Rohingya have been killed by wild elephants whose habitat has been consumed by Kutupalong refugee camp. (Photo by Munir Uz Zaman/AFP Photo)

A military band playing during the Immortal Regiment march in Vladivostok, Russia on May 9, 2016. The celebrations marked the 71st anniversary of the defeat of Germany in WWII. (Photo by Yuri Smityuk/TASS/Getty Images)

Miss Venezuela Edymar Martinez poses during the swimsuit contest during the Miss International beauty pageant in Tokyo on November 5, 2015. Martinez won the Miss International title. Representatives of 70 countries and regions from all over the world took part in the annual beauty contest. (Photo by Toru Yamanaka/AFP Photo)

Londoners enjoying the magnificent sight of sun setting perfectly in the middle of London Eye as seen from Greenwich Park in London, England on the warmest day of the year on April 19, 2018. (Photo by London Viewpoints/Rex Features/Shutterstock)