A.用2m托線板檢查 B.用方尺和塞尺檢查 C.用2m靠尺和塞尺檢查 D.用直尺和塞尺檢查
A.4mm B.1mm C.2mm D.3mm
A.6m,15m B.4m,20m C.6m,20m D.4m,15m