单项选择题
A.40cm;30cm B.30cm;40cm C.20cm;40cm D.40cm;20cm
A.0.3x0.5m;0.75x0.75m B.0.75x0.75m;0.3x0.5m C.2x1m;2x4m D.0.3x0.5m;2x1m
A.4.0m B.3.0m C.2.0m D.1.0m