单项选择题
A.10 B.15 C.20 D.25
A.50 B.55 C.60 D.65
A.25 B.35 C.45 D.55
A.90% B.80% C.70% D.60%
A.50% B.60% C.70% D.80%
A.70% B.80% C.85% D.90%
A.70% B.90% C.80% D.85%
A.70% B.75% C.80% D.85%
A.1000 B.800 C.500 D.300
