单项选择题
A.0.4m B.0.2m C.0.6m D.0.8m
A.(1:0.5)~(1:1) B.(1:0.2)~(1:0.7) C.(1:0.5)~(1:0.7) D.(1:0.2)~(1:0.7)
A.200m B.300m C.400m D.500m