A.0.5~1.0 B.1.0~2.0 C.2.0~2.5 D.2.5~3.0
A.5%,10% B.10%,5% C.1%,5% D.5%,1%
A.勻質(zhì) B.上層粒徑大,下層粒徑小 C.非勻質(zhì) D.上層粒徑小,下層粒徑大