单项选择题
A.0.4m;2根 B.0.5m;3根 C.0.6m;4根 D.0.3m;1根
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