短语词组短语seal -off mercury-arc rectifier 封闭汞弧整流器seal sth off 封锁;翻译seal l off 把……封锁起来Seal -off 密封式lead seal pack off 铅封封隔seal off from isolate 阻隔blockade block seal off 用强制力量使与外界断绝联系或往来fault seal off 断层封堵 返回 seal off