North Korean commuters are seen through a door window waiting to board a train in a subway train station in Pyongyang, North Korea, 14 April 2017. North Koreans are preparing to celebrate the “Day of the Sun” festival, commemorating the 105th birthday anniversary of former supreme leader Kim Il-sung on 15 April, as tension over nuclear issues rise in the region. (Photo by How Hwee Young/EPA)

“Sperm whale opening it's huge mouth, Ogasawara Islands, Japan. Sperm whales are the biggest carnivorous animals on the planet. Each teeth in the mouth of adult specimen weights more than 1 kilogram. Interestingly enough that modern marine biologists believe that these teeth despite being fearsome play little role in capturing and eating giant squid – with their main function being mainly ritual aggression between males!”. (Photo by Alexander Safonov)

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)

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)

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)