Participants in costumes pose before a Halloween parade in Kawasaki, south of Tokyo, Japan on October 28, 2018. (Photo by Toru Hanai/Reuters)

A fisherman throws a net for catching fish with his wife in Yanhu fisherman village near Yangzhou, Jiangsu province, China, 18 October 2018. (Photo by Aleksandar Plavevski/EPA/EFE)

Indian children dressed up as the Hindu deities Rama and Sita take a selfie photograph at an event to celebrate the Diwali festival in Ajmer in western Rajasthan state on November 6, 2018. (Photo by Shaukat Ahmed/AFP Photo)

Workers carry a metal sheet at a dockyard in Dhaka, Bangladesh, December 5, 2018. (Photo by Mohammad Ponir Hossain/Reuters)

A truck carrying gold miners across the Sahara desert to far northern Niger drives outside Agadez, Niger, May 9, 2016. (Photo by Joe Penney/Reuters)

A group of fashionable nonagenarians pose for a photo in Pengzhou, Sichuan, China on October 12, 2016. (Photo by Rex Features/Shutterstock)

Commuters hang off a local passenger train in the morning in Colombo, Sri Lanka September 8, 2016. (Photo by Dinuka Liyanawatte/Reuters)

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)