A.提高日增重 B.防止缺鐵性貧血 C.防止下痢 D.增強(qiáng)免疫力
A.0.01% B.0.02% C.0.03% D.0.05%
A.55分貝 B.65分貝 C.75分貝 D.85分貝
A.40%~50% B.50%~60% C.60%~70% D.70%~80%
A.碘 B.硒 C.錳 D.鋅