警察严肃地审问嫌疑人。

The ___police officer is seriously questioning the suspect.

警车在城市街道上飞驰。

The ___police car speeds through the city streets.

警察在街上巡逻以确保安全。

The ___police are patrolling the streets to ensure safety.

志愿者们在活动中维持秩序，确保每个人都遵守规则。

Volunteers ___police the event to make sure everyone follows the rules.