施用化肥可增加土壤中重金属的积累。
参考答案：对
— What are they doing?
— They are ______________. [ ]
A. play
B. talk
C. laughing
黑膏药的工艺流程是（）
A.炼油→下丹成膏→药料提取→去"火毒"→摊涂
B.药料提取→去"火毒"→炼油→下丹成膏→摊涂
C.药料提取→炼油→下丹成膏→去"火毒"→摊涂
D.药料提取→炼油→去"火毒"→下丹成膏→摊涂
E.药料提取→炼油一摊涂→下丹成膏→去"火毒"
