A.1:1.00~1:125 B.1:075~1:1.00 C.1:0.50~1:0.75 D.1:1.25~1:1.50
A.0.5 B.0.7 C.1 D.2
A.一定相等 B.后者的抗震等級低 C.后者的抗震等級高 D.前者的抗震等級高,也可能相等