In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)

In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

The Thufa hill in Reykjavik, Friday, October 28, 2016. Parliamentary elections will be held in Iceland on October 29, 2016, more than 250,000 voters are called to elect the new parliament, 63 members of the Althing parliament. (Photo by Frank Augstein/AP Photo)

In this November 30, 2017 photo, Douglas scoops up mud from the bottom of the polluted Guaire River, in search of gold and anything valuable he can sell, in Caracas, Venezuela. Some stretches of the river smell of sewer while others emit a toxic odor of fuel, a stench that stays in ones nose for hours after leaving the water. (Photo by Ariana Cubillos/AP Photo)

Members of the SubCielo company perform during the fifth annual Puerto Rico Circo Fest in San Juan, Puerto Rico, Saturday, March 10, 2018. The festival is held simultaneously in several spots on the streets of the Old San Juan city on March 10–11. (Photo by Ricardo Arduengo/AFP Photo)

An Indian girl student covers her face as a precaution against the coronavirus outbreak, in Mumbai, India, 12 March 2020. According to media reports, more than 70 people in India have tested positive for COVID-19. The World Health Organisation declared the novel coronavirus or COVID-19 as global pandemic. (Photo by Divyakant Solanki/EPA/EFE/Rex Features/Shutterstock)

A 9 year old girl receives digital lessons from the primary school teacher in Rotterdam, Netherlands on April 20, 2020, because the schools are closed due to the corona crisis staying at home. Many schools are putting together a homework package or using digital teaching methods, now that education has been closed for several weeks due to the corona virus. (Photo byRobin Utrecht/Rex Features/Shutterstock)

A mahout washes an elephant in the river in Pinnawala, some 95 kms from the capital Colombo on April 15, 2020. (Photo by Ishara S. Kodikara/AFP Photo)