A.（-5）～0mm B.0～5mm C.（-2）～0mm D.0～2mm
A.25个 B.15个 C.20个 D.5个
A.500mm B.300mm C.400mm D.600mm
A.±20 B.＋50，－30 C.±10 D.＋50，0
A.1000-100mm B.10000-10mm C.1000＋10-5mm D.1000＋100mm
