An Iraqi military vehicle passes displaced Iraqi boys returning to their homes in West Mosul's Oreibi neighbourhood after government forces retook control of the area from the Islamic State (IS) group during the ongoing offensive against the jihadists on May 21, 2017. (Photo by Ahmad Al-Rubaye/AFP Photo)

People walk along the Neva River at sunset in St.Petersburg, Russia, Tuesday, December 6, 2016. The temperature in St.Petersburg is –9C ( 15.8 °F). (Photo by Dmitri Lovetsky/AP Photo)

A view of one of the dioramas contained inside iron boxes as part of the “S.A.C.R.E.D” installation by Chinese artist Ai Weiwei during a media preview at the cathedral in Cuenca, Spain, July 21, 2016. Ai Weiwei has reproduced scenes of his incarceration for a new art installation, a series of almost life-size dioramas – encased in steel boxes – showing his life in jail. (Photo by Susana Vera/Reuters)

A fishmonger carries a shark on his motorcycle in Padang, West Sumatra, Indonesia August 25, 2016. (Photo by Iggoy el Fitra/Reuters/Antara Foto)

Capturing this picture of lightning striking near Blackpool Tower has earned Stephen Cheatley the UK Weather Photographer of the Year award 2018. (Photo by Stephen Cheatley/Bav Media)

An Indian student warms up during the 44th Samartha Summer Sports Coaching Camp organized by Shree Samarth Vyayam Mandir in Mumbai, India, 25 April 2018. Mallakhamba arose in the western state of Maharashtra centuries ago. It was originally practiced by wrestlers and soldiers as a strength training exercise. (Photo by Divyakant Solanki/EPA/EFE)

Costumed dancers parade on the first day of the annual Qoyllur Rit'i festival on May 27, 2018 in Ocongate, Peru. Every year, since 1783 in the Sinakara Valley at the foot of Mt Ausagante, the Qoyllur Rit'i, or “Snow and Star” festival draws tens of thousands of pilgrims from across the Peruvian Andes and beyond to what is the biggest religious gathering of its kind. Since 1780 the event merged into a mosaic of indigenous, pagan and Catholic worship when an image of Jesus appeared on a boulder after the death of a young shepherd. (Photo by Dan Kitwood/Getty Images)

An Embraer E-190 E2 aircraft featuring a spray painted tiger's face on the nose of the aircraft is displayed during a media preview of the Singapore Airshow February 4, 2018. (Photo by Edgar Su/Reuters)