A.α/βX100% B.(α-θ)/(β-θ)X100% C.β(α-θ)/α(β-θ)X100% D.以上都不正確
A.15 B.14 C.17 D.18
A.8.0~8.5 B.8.5~9.0 C.9.0~9.5 D.9.5~10