Students wearing face masks take a class at a school in Cotonou, Benin, May 11, 2020. Students in Benin resumed class on Monday. (Photo by Seraphin Zounyekpe/Xinhua)

Students wear face masks at a school in Cotonou, Benin, May 11, 2020. Students in Benin resumed class on Monday. (Photo by Seraphin Zounyekpe/Xinhua)

Students wearing face masks take a class at a school in Cotonou, Benin, May 11, 2020. Students in Benin resumed class on Monday. (Photo by Seraphin Zounyekpe/Xinhua)

Students wearing face masks take a class at a school in Cotonou, Benin, May 11, 2020. Students in Benin resumed class on Monday. (Photo by Seraphin Zounyekpe/Xinhua)

Students wearing face masks queue up at a school dining hall in Cotonou, Benin, May 11, 2020. Students in Benin resumed class on Monday. (Photo by Seraphin Zounyekpe/Xinhua)

A teacher wearing a face mask gives a lecture at a school in Cotonou, Benin, May 11, 2020. Students in Benin resumed class on Monday. (Photo by Seraphin Zounyekpe/Xinhua)