判断题
A.第一类 B.第二类 C.第三类 D.第四类
A.9m*9m B.10m*10m C.11m*11m D.12m*12m
A.50 B.60 C.70 D.80
A.10 B.20 C.30 D.40
A.0.01B.0.03C.0.05D.0.1