Considered to be a less dangerous alternative to tobacco, "e-cigarettes" are taking over the West as more and more people switch over when trying to kick the habit.
随着越来越多的人开始戒烟,被认为危险程度更小的替代物——电子烟在西方国家流行起来了。
2
That switch, which occurs just as the rats start to master the maze, likely signals that a habit has been formed, says MIT Institute Professor Ann Graybiel, senior author of the PNAS paper.