单项选择题
A.≤0.4uv B.≤0.5uv C.≤0.6uv D.≤0.7uv
A.42007 B.42038 C.42008 D.42067
A.38~42HRC B.48~52HRC C.58~62HRC D.68~72HRC
A.2 B.3 C.1、2 D.2、3
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