sealing off

动词 seal off:

1. make tight; secure against leakage
   同义词：seal, seal off
2. impose a blockade on
   同义词：blockade, seal off

1. It did not seem to occur to the police to seal off the entrance or order nobody to leave.
   警察似乎没有想到应封锁各入口处或命令任何人不得离开。
2. Police sealed off all the exits from the building.
   警方把建筑物的所有出口都封锁住了。