Robot inventor Wu Yulu sits on a rickshaw driven by a robot which he invented in his village in rural Beijing's Tongzhou district, China, 17 November 2016. The 54-year-old Chinese farmer living in rural Beijing's Tongzhou district invented 63 robots in the past 30 years. Wu, who only received primary school education, plans to give up the agricultural work for his robot products. He regularly participates in exhibitions, transfers patent rights and teaches at the university to earn money. (Photo by Wu Hong/EPA)

“The V-30 Warhawk was designed by Blackshaw Avionics as a long-range fighter and was primarily used by the Arcadian Air Force for escort duties. The plane pictured is the “Spirit of Freedom” and was one of the four planes that escorted the Arcadian Royal Airship during and after the Great War. The three other fighters were the “Spirit of Hope”, the “Spirit of Justice” and the “Spirit of Destiny”. All pilots were hand-picked by the Head of Airborne Forces and included some of the very finest pilots in the Kingdom. The crew consisted of one pilot and one gunner although both cabins were fitted so that if either crew member was killed the other could take over their duties. Each Warhawk was fitted with four Haverlock “Banshee” engines and four 24mm machine guns”. (Photo and comment by Jon Hall)

A couple looks at their flooded street from behind their home's window in La Plata, in Argentina's Buenos Aires province, where at least 35 people were killed by flooding overnight, on April 3, 2013. (Photo by Natacha Pisarenko/Associated Press)

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

Thai Buddhist monks wear face shields to protect themselves from new coronavirus as they walk to collect alms from devotees in Bangkok, Thailand, Tuesday, March 31, 2020. (Photo by Sakchai Lalit/AP Photo)

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 local resident dressed as Yamraj or Hindu god of death, wearing a novel coronavirus-themed balloon necklace, gestures as he poses during an awareness about social distancing and staying at home organised by Delhi police during a nationwide lockdown to slow the spreading of the coronavirus disease (COVID-19), in New Delhi, India, April 28, 2020. (Photo by Adnan Abidi/Reuters)

Tourists wearing protective face masks walk in Nanluoguxiang alley, a famous touristic spot at Hutong neighborhood, in Beijing, China, 01 May 2020. China is loosening up nationwide restrictions after months of lockdown over the coronavirus crisis. Labor Day in the country kicked off with a long weekend and an extended holiday, from 01 to 05 May, after the tourism industry has been hit during the coronavirus and COVID-19 disease pandemic. (Photo by Roman Pilipey/EPA/EFE)