#时事英语#上海规定遇红色警报学校停课。严重污染时学校停课suspend classes on heavily polluted days；应急预案emergency response plan；四级污染预警系统a four-tier color alert system；停产halt production；暂停建筑工地作业construction sites to be closed temporarily。
北京周报
#时事英语#上海规定遇红色警报学校停课。严重污染时学校停课suspend classes on heavily polluted days；应急预案emergency response plan；四级污染预警系统a four-tier color alert system；停产halt production；暂停建筑工地作业construction sites to be closed temporarily。