Students wearing face masks are seen in a classroom of a school in Colombo, Sri Lanka, on July 6, 2020. According to Sri Lankan Ministry of Education, students from Grade 5, 11 and 13 resumed schooling on Monday. (Photo by Ajith Perera/Xinhua)

Students wearing face masks are seen in a classroom of a school in Colombo, Sri Lanka, on July 6, 2020. According to Sri Lankan Ministry of Education, students from Grade 5, 11 and 13 resumed schooling on Monday. (Photo by Ajith Perera/Xinhua)

Students wearing face masks are seen in a classroom of a school in Colombo, Sri Lanka, on July 6, 2020. According to Sri Lankan Ministry of Education, students from Grade 5, 11 and 13 resumed schooling on Monday. (Photo by Ajith Perera/Xinhua)

Students wearing face masks line up to wash hands at a school in Colombo, Sri Lanka, on July 6, 2020. According to Sri Lankan Ministry of Education, students from Grade 5, 11 and 13 resumed schooling on Monday. (Photo by Ajith Perera/Xinhua)