Blizzards create white-out conditions. A white-out is when snow is falling fast and winds drive the snow so much that is impossible to see. Driving a vehicle in driving snow can be deadly. Cities sometimes declare a temporary state of emergency. This tells people to stay off the roads. This prevents accidents and also lets the snow removal trucks do their work.___________________________暴风雪会造成雪盲.雪盲是指由于雪花急落风力强劲而不能看清楚的情况.在暴风雪天气中驾驶车辆可能是致死的.有时候各城市会发布临时紧急状况.警告人们远离公路.以防止交通事故,并让除雪车进行作业.________________________