Yaks head towards the Everest base camp in Solukhumbu District April 28, 2014. (Photo by Navesh Chitrakar/Reuters)

People look at home-made armoured vehicle look-alikes on a street in Shenyang, Liaoning province, November 12, 2014. A man surnamed Zhang and his friends converted two cars into these two vehicles, for his son, and will be displaying them on show at a local park. The cannons on the vehicles can fire paintballs and smoke shells, local media cited Zhang as saying. (Photo by Reuters/Stringer)

Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

“Two Brothers”. We found about 20 lions eating a buffalo. When the male leaved the group we anticipated him to take photos. It is 8AM, light is perfect and the position too. The lion stops and looks down from the hill, another lion is coming up, it stiffens, I think that will be a fight, i'm tense, the camera is OK, the shots previously made perfect. The two meet, looking directly into their eyes, they sniff, rub against their heads, the tension drops, they start walking with the same step as when they were puppies, they are two brothers. Photo location: Masai Mara, Kenya. (Photo and caption by Massimo Mei/National Geographic Photo Contest)

An Iraqi man cooks traditional Masgouf fish on a barbecue for sale in the Karada market July 02, 2014. Masgouf, one of the national dishes of Iraq is a grilled carp seasoned with olive oil, rock salt, tamarind and ground turmeric. (Photo by Scott Nelson for the Washington Post)

A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

This photo taken on January 30, 2020 shows officials in protective suits checking on an elderly man wearing a facemask who collapsed and died on a street near a hospital in Wuhan. AFP journalists saw the body on January 30, not long before an emergency vehicle arrived carrying police and medical staff in full-body protective suits. The World Health Organization declared a global emergency over the new coronavirus, as China reported on January 31 the death toll had climbed to 213 with nearly 10,000 infections. (Photo by Hector Retamal/AFP Photo)

Young Lebanese women wearing protective masks and gloves against the coronavirus pandemic, stand on August 5, 2020 amid the rubble in Beirut's Gimmayzeh commercial district which was heavily damaged by the previous day's powerful explosion that tore through Lebanon's capital, resulting from the ignition of a huge depot of ammonium nitrate at the city's main port. Rescuers searched for survivors in Beirut after a cataclysmic explosion at the port sowed devastation across entire neighbourhoods, killing more than 100 people, wounding thousands and plunging Lebanon deeper into crisis. The blast, which appeared to have been caused by a fire igniting 2,750 tonnes of ammonium nitrate left unsecured in a warehouse, was felt as far away as Cyprus, some 150 miles (240 kilometres) to the northwest. (Photo by AFP Photo/Stringer)