Police sealed off all roads leading to the town. 警察封锁了通向该城镇的所有道路。
Their aim was to block guerrilla supply lines. 他们的目的是封锁游击队的供给线。
As the rotor turns clockwise the charge is sealed off and compression begins. 当转子顺时针方向转动时，送进的气团就被封闭，并开始压缩。
For instance, he recalls meeting with the town mayor to ask permission to block off streets for a student fundraiser. 举例来说，他记得有一次必须会见该市市长请求封闭街道来进行学生募款运动。
