______ talk! The baby is sleeping.[ ]
A. Not
B. Please
C. Don't
D. Doesn't
答案：C
Not having found __________，he had to go home with empty hands．
A．something
B．everything
C．anything
D．nothing
( )是指各个数据文件中重复的数据。
A．数据组装
B．数据查询
C．数据冗余
D．数据分解
