The researchful objects in this paper include: talk-back system of video,CCTV, guard system of perimeter and house access control system management system of parking lots,background music system etc.是什么意思_The researchful objects in this paper include: talk-back system of video,CCTV, guard system of perimeter and house access control system management system of parking lots,background music system etc.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句