A United States Air Force (USAF) F-15 fighter jet travels at low altitude through the “Mach Loop” series of valleys near Dolgellau, north Wales on June 26, 2018. The Mach Loop valleys, situated between Dolgellau and Machynlleth, are regularly used by the military for operational low flying training which can take place as low as 76 metres from the nearest terrain. The USAF regularly use the loop to practice low-altitude flight, which confuses radar systems. (Photo by Oli Scarff/AFP Photo)

People decorate a street with candles inside oranges during the Epitaph ceremony during Good Friday's “Apokathelosis”, the Descent of Christ's dead body from the Cross, which forms a key part of Orthodox Easter, in the southern city of Leonidio, at the Peloponnese peninsula on April 26, 2019. Millions of Greeks flock to churches around the country this week to celebrate Easter, the country's foremost religious celebration. (Photo by Aris Messinis/AFP Photo)

Two animatronic velociraptors are on display during a technical rehearsal of “Walking with Dinosaurs The Live Experience” at the Indoor Stadium in Singapore, 29 August 2019. “Walking with Dinosaurs The Live Experience” is based on the BBC series of the same name and will run from 29 August to 08 September. (Photo by Wallace Woon/EPA/EFE/Rex Features/Shutterstock)

In this Saturday, May 7, 2016 photo, Afghan refugee Shazia Lutfi, 19, peeks through the door of her room at the former prison of De Koepel in Haarlem, Netherlands. The government has let Belgium and Norway put prisoners in its empty cells and now, amid the huge flow of migrants into Europe, several Dutch prisons have been temporarily pressed into service as asylum seeker centers. (Photo by Muhammed Muheisen/AP Photo)

A cooling tower is seen under mechanical demolition in Binzhou, Shandong Province, China, July 13, 2016. (Photo by Reuters/China Daily)

This is the moment a dog who had his legs cut off as a punishment, is able to walk again thanks to prosthetic limbs, and being rescued by John and Gill Dalley, a couple who moved to Phuket, Thailand, from Leeds to set up the Soi Dog Foundation, August 1, 2016. (Photo by Caters News Agency)

Tube passengers take a selfie next to a London underground roundel designed for the launching of the Night Tubes on display at Oxford Circus underground station in London, Britain, 19 August 2016. The long delayed Night Tubes service launched on 19 August. The 24-hour service will operate on Fridays and Saturdays. (Photo by Hannah Mckay/EPA)

Employees stand near an airframe for the second Antonov-225 Mriya plane at Antonov aircraft plant in Kiev, Ukraine, September 7, 2016. Ukraine hopes to attract $500 million of investment from China to complete an updated version of the world's biggest aircraft, the Antonov-225 Mriya, the president of manufacturer Antonov said on Wednesday. (Photo by Valentyn Ogirenko/Reuters)