The phototube, a very special type of electron tube, is the heart of the talking - picture projector.

光电管, 一种非常特殊的电子管, 是有声电影放映机的心脏.

辞典例句

No later than 1890, he combined his moving - picture projector with his talking machine.

不迟于1890年, 他就把他的电影放映机和他的会说话的机器结合起来.

辞典例句