单项选择题
A.50tB.120tC.20tD.60t
A.90mmB.50mmC.30mmD.120mm
A.20±2B.20±5C.23±5D.21±2
A.0.03~0.05B.0.05~0.08C.0.02~0.05D.0.08~0.10
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