单项选择题
A.轴承钢 B.渗碳轴承钢 C.塑钢 D.中碳钢
A.轴承钢 B.工程塑料 C.塑钢 D.中碳钢
A.0.025~0.508mm B.0.025~0.54mm C.0.025~0.58mm D.0.075~0.54mm
A.0.075-0.5mm B.0.075-0.45mm C.0.075-0.52mm D.0.075-0.54mm
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