∵a+1a=6,
∴a2+2+1a2=36,
∴a2+1a2=36-2=34.
He ______________ three sisters. [ ]
A. is
B. has
C. have
现有三组混合液:(1)乙酸乙酯和乙酸钠溶液;(2)乙醇和甲醇;(3)溴化钠和单质溴的水溶液,分离以上各混合液的正确方法依此是[ ]
A.分液、蒸馏、萃取
B.萃取、分液、蒸馏
C.萃取、蒸馏、分液
D.分液、萃取、蒸馏