Sometimes the fierce animal came out of one door.

VOA: special.2009.04.18

So, what you do is you set up a couple of displays, one where the block is stopped, the other one where you take this away with a trap door and it keeps going.

所以,你可以设计几个演示,一个是木块被挡住了,另一个是用活门把木块挪开,使得屏板继续上升

耶鲁公开课 - 心理学导论课程节选

One day, while I was working in my laboratory, Jules Simon knocked at my door.

VOA: special.2009.07.18

"I am happy." he said, "that I was the first one to open the door -- to let everyone know we could all do it."

VOA: special.2010.03.07

He hears a noise at the window. Here is the beginning of the poem: Once upon a midnight dreary, while I pondered,weak and weary,Over many a quaint and curious volume of forgotten lore -- While I nodded,nearly napping, suddenly there came a tapping, As of some one gently rapping -- rapping at my chamber door.

VOA: special.2010.10.31

Muller remembers hearing violent knocks at the door of her Paris apartment late one night.

VOA: standard.2010.04.10

The crowd outside the courthouse watched anxiously as one by one, each with a canvas-covered bed, backed up to a courtroom door and, out of the view of onlookers, deposited handcuffed defendants for a brief appearance before a judge.

VOA: standard.2009.05.25