单项选择题
A.80%~100% B.60%~80% C.40%~60% D.20%~40% E.0%~20%
A.0%~20% B.20%~40% C.40%~60% D.60%~80% E.80%~100%
A.<1% B.2%~3% C.5% D.8% E.20%