短语词组短語seal -off mercury-arc rectifier 封閉汞弧整流器seal sth off 封鎖;繙譯seal l off 把……封鎖起來Seal -off 密封式lead seal pack off 鉛封封隔seal off from isolate 阻隔blockade block seal off 用強制力量使與外界斷絕聯系或往來fault seal off 斷層封堵 返回 seal off