警车在市中心来回巡逻，保持治安稳定。

Jǐngchē zài shì zhōngxīn láihuí xúnluó, bǎochí zhì'ān wěndìng.

Police cars patrol back and forth in the city center to keep public security stable.

节日期间，警察加大了在景区巡逻的力度。

Jiérì qījiān, jǐngchá jiādà le zài jǐngqū xúnluó de lìdù.

During the holidays, the police increased their patrols in the scenic area.

晚上小区门口都有保安巡逻。

Wǎnshang xiǎoqū ménkǒu dōu yǒu bǎo'ān xúnluó.

At night there are security guards patrolling at the entrance of the residential compound.