Students attend their first day back to in-person class amid the COVID-19 pandemic at a public school in Montevideo, Uruguay, Monday, March 1, 2021. Uruguay is returning most of its students to in-person classes after the summer holidays. (AP Photo/Matilde Campodonico)

A girl attends her first day back to in-person class amid the COVID-19 pandemic at a public school in Montevideo, Uruguay, Monday, March 1, 2021. Uruguay is returning most of its students to in-person classes after the summer holidays. (AP Photo/Matilde Campodonico)

A teacher speaks to students on their first day back to in-person class amid the COVID-19 pandemic at a public school in Montevideo, Uruguay, Monday, March 1, 2021. Uruguay is returning most of its students to in-person classes after the summer holidays. (AP Photo/Matilde Campodonico)

Students leave the classroom for a break on their first day back to in-person class amid the COVID-19 pandemic at a public school in Montevideo, Uruguay, Monday, March 1, 2021. Uruguay is returning most of its students to in-person classes after the summer holidays. (AP Photo/Matilde Campodonico)

Students take a recess on the playground during their first day back to in-person class amid the COVID-19 pandemic at a public school in Montevideo, Uruguay, Monday, March 1, 2021. Uruguay is returning most of its students to in-person classes after the summer holidays. (AP Photo/Matilde Campodonico)