With more teachers sickened or sidelined by the highly contagious Omicron variant, school districts across the country have resorted to extraordinary measures to keep classrooms running.
원문출처 : https://www.cnn.com/2022/01/11/us/teacher-shortages-parents-substitutes/index.html
원문출처 : https://www.cnn.com/2022/01/11/us/teacher-shortages-parents-substitutes/index.html