SR: So the same way that building lights at night let you know that somebody's probably working there at any given moment, in a very real sense, there are biological sensors within a cell that are turned on only when that cell was just working.
史蒂夫：这就好比通过夜晚的大楼灯光， 你可以推知有人可能在某一时段在那里工作过。 事实上，每一个细胞中都有一些传感器， 这些传感器 只有在该细胞工作时开启。