patrol/pə'trəul/

1.noun [c] 
(group) 巡逻队

2.noun [c/u] 
(activity) 巡逻

3.vt.[+city] [ streets] [ area] 
在…巡逻

to be on patrol
在巡逻中
to do a patrol (of sth)
(对某处)进行巡逻