A protester reacts during a rally against the government's restrictions following the coronavirus disease (COVID-19) outbreak, in Berlin, Germany, August 29, 2020. (Photo by Christian Mang/Reuters)

A woman reacts as she receives the AstraZeneca/Oxford vaccine under the COVAX scheme against coronavirus disease (COVID-19) at the Kenyatta National Hospital in Nairobi, Kenya on March 5, 2021. (Photo by Monicah Mwangi/Reuters)

South Korean football fans react during a public screening in Seoul of the South Korea vs Russia football match at the 2014 World Cup in Brazil, early on June 18, 2014. (Photo by Ed Jones/AFP Photo)

A Palestinian man reacts after his house was flooded by rain water in Khan Younis in the southern Gaza Strip, November 9, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

These beautiful shots may look like works of modern art – but they are actually close-ups of chemical reactions. The works were snapped with the help of a group of scientists from the University of Science and Technology of China (USTC) in Anhui, China. Here: Zinc reacting with lead nitrate in a soft gel to form lead crystals. (Photo by Yan Liang/Caters News)

Ukraine's Maryna Bekh-Romanchuk reacts during the women's triple jump final at the World Athletics Indoor Championships in Belgrade, Serbia on March 20, 2022. (Photo by Bernadett Szabo/Reuters)

A girl reacts as coloured water is thrown on her face while celebrating Holi, the Festival of Colours, in Mumbai, India, March 13, 2017. (Photo by Shailesh Andrade/Reuters)

A girl reacts as she is tattooed during the third International Tattoo Week Rio 2016 festival in Rio de Janeiro, Brazil, January 22, 2016. (Photo by Pilar Olivares/Reuters)