Definition: to put something across the entrance to a place in order to stop people entering it Level: C1
事故发生后，警方封锁了街道。
The police ___closed ___off the street after the accident.
几条道路因马拉松赛而被封闭。
Several roads were ___closed ___off for the marathon.
为确保安全，他们用路障封锁了建筑工地。
To ensure safety, they ___closed ___off the construction site with barriers.
