A teacher instructs students to check their temperature in Glyfada, a southern seaside suburb of Athens, Greece, on Sept. 14, 2020. The new school year started for Greek students on Monday as safety measures were enforced at schools to curb the spread of COVID-19. (Xinhua/Marios Lolos)

Pupils of a primary school wearing face masks enter their school in Glyfada, a southern seaside suburb of Athens, Greece, on Sept. 14, 2020. The new school year started for Greek students on Monday as safety measures were enforced at schools to curb the spread of COVID-19. (Xinhua/Marios Lolos)

Pupils of a primary school wearing face masks enter their school in Glyfada, a southern seaside suburb of Athens, Greece, on Sept. 14, 2020. The new school year started for Greek students on Monday as safety measures were enforced at schools to curb the spread of COVID-19. (Xinhua/Marios Lolos)

School teachers wearing face masks instruct pupils at a primary school in Glyfada, a southern seaside suburb of Athens, Greece, on Sept. 14, 2020. The new school year started for Greek students on Monday as safety measures were enforced at schools to curb the spread of COVID-19. (Xinhua/Marios Lolos)