Schoolgirls of the fifth year voluntarily wear protective face masks inside their classroom as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

Students of Government Secondary School Wuse, are seen taking the West African Examination Council (WAEC) 2020 exam, after the coronavirus disease (COVID-19) lockdown in Abuja, Nigeria August 17, 2020. REUTERS/Afolabi Sotunde

Schoolgirls and schoolboys of the fifth year voluntarily wear protective face masks inside their classroom as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

A high school student wears a protective face mask as she attends final exams amid concerns of the spread of the coronavirus disease (COVID-19) in Sanaa, Yemen August 15, 2020. REUTERS/Khaled Abdullah

Students and teachers wear protective face masks while keeping social distance as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

Schoolgirls of the fifth year voluntarily wear protective face masks inside their classroom as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

Director Juergen Scheuermann welcomes students as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

Schoolgirls and schoolboys of the fifth year voluntarily wear protective face masks inside their classroom as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

Students wear protective face masks while keeping social distance as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

A sign reads "Social distance" as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

A sign reads "Keep distance" as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

A sign reads "Social distance" as schools re-open after summer holidays and the lockdown due to the outbreak of the coronavirus disease (COVID-19) at the Karl-Rehbein high school in Hanau, Germany, August 17, 2020. REUTERS/Kai Pfaffenbach

Abdel-Rahman Al-Shantti, an 11-year-old Gaza rapper, talks with his father after returning home from school in Gaza City August 16, 2020. Picture taken August 16, 2020. REUTERS/Mohammed Salem