A.0.01-0.02B.0.01-0.04C.0.01-0.06D.0.01-0.08
A.10~30m3/(m2?d)B.20~50m3/(m2?d)C.30~70m3/(m2?d)D.40~80m3/(m2?d)
A.10%~20%B.20%~30%C.25%~35%D.30%~40%