单项选择题
A.HR; B.Hr; C.HB; D.HS;
A.大头; B.小头; C.中间; D.平均;
A.1cm; B.25.4mm; C.1mm; D.1dm;
A.直径; B.大径; C.中径; D.小径;
微信扫一扫,加关注免费搜题