backern.援助者;支持者(物)Backer.n.衬料
backbonen.脊骨;骨干;骨气;毅力
backdrops背景布幕
backdrop manhole后级沙井;跌级沙井
backdrop procedure背景程序
backdrop of violence暴力冲突不断
backdrop of New Villages新农村背景
backdrop to the new initiatives新提案的背景