A.硫、鈉、氧 B.硫、氮、氧 C.硫、氮、鎂 D.氮、氧、鉀
A.1/4~2/4 B.1/4~3/4 C.1/2~2/3 D.1/3~2/3
A. 0.3-0.4 B. 0.4-0.5 C.0.5-0.6