红色预警 red alert
Under the red alert, the government authorities adopt many measures to help urban residents combat the smog.
发出红色预警之后，政府各部门采取多项措施帮助市民抗击雾霾。
The red alert is the highest in the city’s four-tier emergency response system.
红色预警是该城市应急响应系统中的最高级别。
