数据库具有最小冗余度、较高的程序与数据独立性，易于扩充和 ______ 的特点。
A．程序结构化
B．程序标准化
C．数据模块化
D．共享
参考答案：D
—Where are the twins?
—I think they ______ Hangzhou. They ______ there twice before. [ ]
A. have been to; have gone to
B. have gone to; have been
C. have been to; have been to
D. have gone to; have gone
—Do you have classes at 8:00 in the morning?
— [ ]
A. No, I don't
B. Yes, I don't
C. No, I do
D. Yes, I does
