A.4 CM(含4 CM) B.5 CM(含5 CM) C.8 CM(含8 CM) D.10 CM(含10 CM)
A.C1/C3>1 B.C2/C1<1 C.C2/C3≤1 D.C2/C3≥1
A.30% B.50% C.10% D.20%