题目

测定饮用水中大肠杆菌的数目可用（   ） A . 选择培养基 B . 鉴别培养基 C . 基础培养基 D . 加富培养基 答案：BWhen she was alone at home, she liked to ________.A.say to herselfB.enjoy himselfC.say to othersD.teach themselves