题目

现有①乙酸乙酯和乙酸钠溶液、②溴化钠溶液和溴水的混合液，分离它们的正确方法依次是 A.分液、蒸馏             B.萃取、分液               C.分液、萃取             D.蒸馏、分液 答案：C解析：①中加入饱和Na2CO3溶液然后分液，②中加入苯或CCl4萃取，故答案为C项。Tom is said ________ a new computer program recently，but I don't know when he'll finish it. A．to design  　B．to be designing C．to have been designing  　D．to have designed