For example, theater scenery used to consist of large painted backdrops raised and lowered by stagehands who would whistle to signal each other.

比如，过去剧院的布景由大型的彩绘背景组成，由舞台工作降，他们会用吹口哨的方式互相传递信。

At the back of the stage in most theatres there's a " backdrop, " a large curtain.

在大多数剧院的舞台后方，有个“背景”，块大布。

Harry's gaze wandered to the portrait that sometimes contained Phineas Nigellus Black, Sirius's great-great grandfather, but it was empty, showing nothing but a stretch of muddy backdrop.

哈利的目光徘徊在菲尼亚斯? 奈杰勒斯的肖像框上--他是小天狼星的曾曾祖父。但是现在像框里什么都没有，只有个泥泞的背景。