单项选择题
A.水平 B.倾斜 C.垂直 D.水平或倾斜
A.10-20mm B.30-40mm C.40-50mm D.20-30mm
A.180° B.120° C.90° D.60°
A.0.10mm B.0.15mm C.0.20mm D.0.25mm
微信扫一扫,加关注免费搜题