A.3°~5° B.1°~3° C.5°~7° D.7°~9°
A.10%~30% B.30%~50% C.50%~70% D.70%~90%
A.65 B.70 C.75 D.80
A.1 B.2 C.3 D.4
A.10%~20% B.20%~30% C.40%~50% D.50%~60%