High school students wearing face masks study in an outdoor area at a school in central Israeli city of Modiin, on Nov. 29, 2020. On Sunday, high school classes in Israel resumed in cities and towns defined as "green" or "yellow," with a low morbidity level of the virus. (Photo: Xinhua)

High school students wearing face masks study in an outdoor area at a school in central Israeli city of Modiin, on Nov. 29, 2020. On Sunday, high school classes in Israel resumed in cities and towns defined as "green" or "yellow," with a low morbidity level of the virus. (Photo: Xinhua)

High school students wearing face masks study in an outdoor area at a school in central Israeli city of Modiin, on Nov. 29, 2020. On Sunday, high school classes in Israel resumed in cities and towns defined as "green" or "yellow," with a low morbidity level of the virus. (Photo: Xinhua)

High school students wearing face masks study in an outdoor area at a school in central Israeli city of Modiin, on Nov. 29, 2020. On Sunday, high school classes in Israel resumed in cities and towns defined as "green" or "yellow," with a low morbidity level of the virus. (Photo: Xinhua)