问题描述：
橡胶的硬度在70-80度,请问要用哪种材料,请具体说明
material must be kind of rubber with hardness of 70shorA to 80shoreA
是做耳机用的,要求防水.
material must be kind of rubber with hardness of 70shorA to 80shoreA
是做耳机用的,要求防水.
问题解答：
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