A.30m
B.50m
C.80m
D.100m
A.115~4000Hz(1/1倍频程)
B.120~4000Hz(1/1倍频程)
C.125~4000Hz(1/1倍频程)
D.130~4000Hz(1/1倍频程)
A.楼梯间
B.小于5平方米卫生间
C.小于10平方米办公用房
D.配电室
B.31m
C.32m
D.33m
A.一级
B.二级
C.三级
D.四级
A.20m
B.30m
C.40m
D.50m