A young boy plugs his ears as his sister (C) and nanny (L) watch from Gravelly Point Park as planes land at Reagan National Airport in Arlington, Virginia on June 29, 2017. President Donald Trump' s travel ban on people from six mostly Muslim countries will come into force late Thursday, as controversy swirls over who qualifies for an exemption based on family ties. (Photo by Jim Watson/AFP Photo)

A Monster Jam truck performs a back flip during the first-ever monster truck event in Beijing's iconic “Bird's Nest” National Stadium on Saturday, July 29, 2017. (Photo by Ng Han Guan/AP Photo)

Festival crowd enjoying the weather on Day 1 of Reading Festival on August 25, 2017 in Reading, England. (Photo by Dean Fardell/Barcroft Images)

Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

Charlotte Caslick of Australia is tackled by Jasmine Joyce of Wales during the Rugby Sevens Women's Pool B match between Australia and Wales on day nine of the Gold Coast 2018 Commonwealth Games at Robina Stadium on April 13, 2018 on the Gold Coast, Australia. (Photo by Dan Mullan/Getty Images)

A Flame Skimmer or Firecracker Skimmer dragonfly (Libellula saturata) rests on a small branch in Topanga, California, USA, 18 June 2018. The Flame Skimmer dragonfly is found in the Western United States near ponds and creeks. (Photo by Mike Nelson/EPA/EFE)

Two brown bears bathe in their enclosure at the Wildpark Poing in Poing, Germany, Wednesday, August 8, 2018. (Photo by Lino Mirgeler/Deutsche Presse-Agentur via AP Photo)

A green rosella and a wallaby, known as a Pademelon, eye off as they drink from a water bowl put out for thirsty wild animals at a back-yard in Kayena, in northern Tasmania, 01 February 2019. Australia recorded its hottest month on record in January; it was also the hottest and driest month on record for the Australian island state of Tasmania. (Photo by Barbara Walton/EPA/EFE)