单项选择题
A.3B.4C.5D.6
A.+2,-2B.+3,-2C.+4,-2D.+5,-3
A.+3mm,-2mmB.±2mmC.+6mm,-2mmD.+4mm,-2mm
A.10B.12C.14D.16
微信扫一扫,加关注免费搜题