单项选择题
A.±6"n B.±6" C.±6"/n D.±6"/
A.n B.1/n C. D.
A.±10.8mm,1/12200 B.±9.4mm,1/14100 C.±4.7mm,1/28200 D.±5.4mm,1/24500
A.+54"、+9" B.-54"、+9" C.+54"、-9" D.-54"、-9"
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