My father is a teacher. ______ phone number is 546807. [ ]
A. He
B. His
C. She
D. Her
答案:B
活化剂与下列哪种药品搭配使用()
A、缓蚀阻垢剂
B、氧化性杀菌灭藻剂
C、非氧化性杀菌灭藻剂
D、粘泥剥泥剂
挥发分含量对燃料燃烧特性影响很大,下列挥发分含量最高的煤种是()。
A.无烟煤
B.烟煤
C.贫煤
D.褐煤