The professor, whose hobby was photography, had also left an unexposed photographic plate under a stack of books on a table in the same room.Later he used the plate to take a picture of some scenery.

• 教授爱好摄影，在此之前他曾把一块尚未曝光的感光板放在实验室桌上的一堆书下面，后来他用这块感光板拍了一张风景照。