预警
Alert / pre-warning / early warning
e.g. 北京开始实行一项空气污染应急方案，包括四个等级的预警。
Beijing beggan to adopt an emergency response programme for air pollution, which includes four-tier alerts.
e.g. 财务风险预警在一个企业中的发展起着非常重要的作用。
Pre-warning for financial risk plays a very important role in the development of an enterprise.
红色预警
red alert
e.g. 这四个等级的预警是蓝色、黄色、橙色和红色预警，将在严重污染的日子发布。
The four-tier alerts are blue, yellow, orange and red alerts, which will be issued on days of heavy pollution.
