brush materials how to differentiate?

As mentioned above, material consists of soft and hard plastic toothbrush, so how do you distinguish between the two kinds of materials? I in here for everyone provides a simple and practical of method: everyone can will a support toothbrush to free fall of way lost to ground Shang, if toothbrush landing voice crisp and rebound of height high, so this support toothbrush handle of material is hard plastic; instead, if a support toothbrush landing Hou no rebound, no crisp of throwing to sound, so this support toothbrush is soft plastic of. In addition, the same model and the same specifications of toothbrushes, hard plastic than soft plastic and easy to break.