A.1.8 m B.2.0 m C.2.2 m D.2.5 m
A.平屋顶 B.瓦屋顶 C.坡屋顶 D.曲屋顶
A.1% B.5% C.1 0% D.1 5%
A.1% B.5% C.10% D.1 5%