OSTRAVA, CZECH REPUBLIC - APRIL 11: Students before entering primary school, where they are waiting for testing for COVID as first to fifth grades return to elementary schools across the country in Ostrava, Czech Republic on April 11, 2021. The Czech government closed all schools due to the COVID-19 pandemic since 01 March 2021. Pupils must be tested by antigen tests for COVID-19 two times a week. Lukas Kabon / Anadolu Agency/ABACAPRESS.COM