A train attendant helps a passenger to adjust her seat at the business class carriage on a CRH 380A bullet train Thursday, June 16, 2011. (Photo by Reuters/China Daily)

Mystical Forest. Tracey Jennings photographed this seven-gill shark in a kelp forest just off the shore of Simon's Town near Cape Town, South Africa. You don't need to travel far from cities to visit Narnia. This 7 gill shark was photographed in a kelp forest just off the shore of Simonstown near Cape Town, South Africa. (Photo by Tracey Jennings/National Geographic Travel Photographer of the Year Contest)

Tomomi Ota visits a local shrine with her humanoid robot Pepper in Tokyo, Japan, 26 June 2016. Reaching 120cm in height and 28 kilograms in weight, Pepper does not enter in the category of portable robot. But those characteristics dont stop Tomomi Ota to take Pepper in a cart to stroll in her neighborhood, go shopping or even take the subway... (Photo by Franck Robichon/EPA)

Local residents crowd a swimming pool during a hot weather in Suining, Sichuan province, 27 July 2008. (Photo by Reuters/Stringer)

People look at huge waves crashing on the San Esteban de Pravia seafront, northern Spanish region of Asturias February 8, 2016. (Photo by Eloy Alonso/Reuters)

A light railway train passes through a residential building on March 18, 2017 in Chongqing, China. Chongqing Rail Transit No.2 and a 19-storey residential building have been built across each other. The railway set its Liziba Station on the sixth to eighth floor in the building with noise reduction equipment. (Photo by VCG/VCG via Getty Images)

Belarusian villagers celebrate the Christmas carol rite (Kalyady) in the village of Danilevichy, some 320 km south of Minsk on January 7, 2020. Kalyady is an ancient pagan holiday originally celebrated on winter solstice. Dressed-up people walk from house to house singing, dancing, eating and drinking with their neighbours. (Photo by Sergei Gapon/AFP Photo)

Gazan artist wears a face mask to raise awareness to the novel coronavirus (Covid-19) spread in Gaza Strip on March 25, 2020. (Photo by Ali Jadallah/Anadolu Agency via Getty Images)