制备5%碘的水溶液，通常可采用以下哪种方法
A．制成盐类B．制成酯类C．加增溶剂D．加助溶剂E．采用复合溶剂
参考答案：D
建立账套 为广源工厂建立一套新账，启用日期为2008年1月，账套主管为考生姓名，账套号为考生代码，增加操作人员XX、YY，密码统一为1。
—I went to your house yesterday afternoon, but you were not in.
—Sorry. I ________ basketball with my classmates. [ ]
A. am playing
B. was playing
C. played
D. have played
