a fly on the ˈwalla person who watches others without being noticed不为人觉察的观察者I'd love to be a fly on the wall when he tells her the news.他把这消息告诉她时，我想悄悄在旁观看。fly-on-the-wall documentaries(= in which people are filmed going about their normal lives as if the camera were not there)纪实影片 |