You can throw a toothbrush on the ground in a free-fall manner. If the toothbrush lands with a crisp sound and the rebound height is high, then the material of the toothbrush handle is hard plastic; on the contrary, if a toothbrush does not rebound after landing, There is no clear sound, so this toothbrush is soft and plastic. In addition, toothbrushes of the same style and specifications are easier to break from hard plastic than soft plastic.
