单项选择题
A.15~30mm B.15~40mm C.25~50mm D.20~45mm
A.800mmB.900mmC.1000mmD.1200mm
A.250mm B.500mm C.750mm D.1000mm
A.200mm B.250mm C.300mm D.400mm
A.5m B.6m C.7m D.8m
A.2m B.3m C.4m D.5m
A.1m B.2m C.3m D.4m
A.800mm B.900mm C.1000mm D.1200mm
A.200mm B.400mm C.600mm D.800mm
A.1000mmB.1200mmC.1500mmD.1800mm