CCTV
uk/ˌsiː.siː.tiːˈviː/ us/ˌsiː.siː.tiːˈviː/
闭路电视（closed-circuit television的缩写）
abbreviation for closed-circuit television : a system that sends television signals to a limited number of screens, and is often used in shops and public places to prevent crime
CCTV cameras 闭路电视摄像机
The whole incident was captured on CCTV. 整个事件被闭路电视摄像机拍摄了下来。