Children carrying guns and flags or wearing Soviet-style uniforms have become a common sight at Victory Day parades and other events in Russian-controlled Crimea. Russian and Ukrainian human rights activists have warned that such displays point to a growing trend of promoting Russian patriotism among kids on the Crimean peninsula, annexed from Ukraine in 2014. Here: A young Crimean girl wears military-type clothes during a Victory Day celebration in Sevastopol on May 9, 2018. (Photo by Oleksandra Surgan/Radio Free Europe/Radio Liberty)

Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

Frogs playing dominos at the Frog Museum, a collection of 108 stuffed frogs in scenes portraying everyday life in the 19th-century and made by Francois Perrier, in Estavayer-le-Lac, Switzerland on November 7, 2018. (Photo by Denis Balibouse/Reuters)

A mahout splashes water on his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India, May 20, 2015. (Photo by Amit Dave/Reuters)

A boy walks with toy guns as people ride an APC during a military show at the Finnish Gulf coast in St.Petersburg, Russia, Saturday, September 5, 2015. (Photo by Dmitry Lovetsky/AP Photo)

A woman eats candy in the shape of a phallus during the Kanamara Matsuri, or Iron Phallus Festival through a street near the Kanamara shrine in Kawasaki outside of Tokyo April 5, 2015. The festival celebrates fertility and is used to raise awareness and money for the prevention of sexually transmitted diseases. (Photo by Thomas Peter/Reuters)

A young Chinese girl kicks during a kung-fu class at Ritan Park on June 11, 2016 in Beijing, China. Ritan, meaning “sun altar”, is among the oldest parks in Beijing, built in the early 1500s during the Ming dynasty for the emperor to make sacrifices to the sun. (Photo by Kevin Frayer/Getty Images)

A vehicle lies on a road in Adairsville. (Photo by David Goldman/Associated Press)