单项选择题
A.±283mmB.±28mmC.±40mmD.±400mm
A.±20mmB.±10mmC.±14mmD.±40mm
A.120±0.040B.120±0.010C.120±0.030D.120±0.020
A.权基数B.加权C.算术平均权D.单位权
微信扫一扫,加关注免费搜题