当局迅速封锁了犯罪现场。

The authorities quickly ___seal ___off the crime scene.

政府因环境危害封锁了旧工厂。

The government ___seal ___off the old factory due to environmental hazards.

调查期间，整个社区被封锁以确保公共安全。

During the investigation, the entire neighborhood was ___seal ___off to ensure public safety.