Students wearing masks are seen outside a school in central Israeli city of Modiin amid COVID-19 pandemic on May 17, 2020. Israeli students in all grades went back to school on Sunday. (Photo by Gil Cohen Magen/Xinhua)

Students wearing masks are seen in a classroom in central Israeli city of Modiin amid COVID-19 pandemic on May 17, 2020. Israeli students in all grades went back to school on Sunday. (Photo by Gil Cohen Magen/Xinhua)

A teacher wearing a mask gives a lesson to students in a classroom in central Israeli city of Modiin amid COVID-19 pandemic on May 17, 2020. Israeli students in all grades went back to school on Sunday. (Photo by Gil Cohen Magen/Xinhua)

Students wearing masks are seen in a classroom in central Israeli city of Modiin amid COVID-19 pandemic on May 17, 2020. Israeli students in all grades went back to school on Sunday. (Photo by Gil Cohen Magen/Xinhua)

Students wearing masks are seen outside a school in central Israeli city of Modiin amid COVID-19 pandemic on May 17, 2020. Israeli students in all grades went back to school on Sunday. (Photo by Gil Cohen Magen/Xinhua)