A.1:2 B.2:1 C.3:1 D.4:1 E.3:2
A.0.6% B.1.6% C.0.2% D.0.1% E.1%
A.98.4% B.99.4% C.99.8% D.99.9% E.99%
A.浅层和深层均致密 B.深层致密,浅层疏松 C.浅层和深层均疏松 D.深层疏松,浅层致密 E.深层、浅层既不疏松,也不致密