A reveller takes part in an annual block party known as “Ceu na Terra” (Heaven on Earth), during carnival festivities in Rio de Janeiro, Brazil February 3, 2018. (Photo by Pilar Olivares/Reuters)

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)

Jaime “Ka Diego” Padilla (R), spokesperson of the Melito Glor Command of the New People's Army (NPA), and Ka Kathryn (Comrade Kathryn) (L) react during their 50th founding anniversary celebration at an undisclosed location in the mountains of Sierra Madre, Philippines, 31 March 2019. (Photo by Alecs Ongcal/EPA/EFE)

People celebrate after Gov. Ricardo Rossello announced that he is resigning Aug. 2 after weeks of protests over leaked obscene, misogynistic online chats, in San Juan, Puerto Rico, Thursday, July 25, 2019. (Photo by Carlos Giusti/AP Photo)

Robots serve trays with food to customers waiting at the Robot theme restaurant in Bangalore, India, 17 August 2019. Six robots are deployed as waiters at the the robot-themed Robot restaurant where each table is equipped with a tablet to place one's order. (Photo by Jagadeesh N.V./EPA/EFE)

A young girl gives a banana to a tamed baboon on the outskirts of Beira, Mozambique, Sunday, March, 31, 2019. Cholera cases among cyclone survivors in Mozambique have jumped to 271, authorities said. So far no cholera deaths have been confirmed. (Photo by Tsvangirayi Mukwazhi/AP Photo)

People are captured by FLIR (Forward-Looking Infrared) HD Thermal Imaging Cameras as they walk near the FLIR exhibit at the Las Vegas Convention Center during CES 2019 in Las Vegas on January 10, 2019. (Photo by David McNew/AFP Photo)

Indian students smear coloured powder during an event to celebrate the Hindu festival of Holi in Kolkata on February 26, 2018. Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 1 this year. (Photo by Dibyangshu Sarkar/AFP Photo)