在对数据流图的分析中，主要是找到中心变换，这是从数据流图导出( )的关键。
A．实体关系
B．程序模块
C．程序流程图
D．结构图
参考答案：D
When immigrants arrived looking forward to the new opportunities and new freedom, they found danger and more hardship in a land devoid of any but the most elementary means of communication.
A．deprived of
B．deluged with
C．diffused by
D．destitute of
称为“娇脏”的是（）。
A.肝
B.心
C.脾
D.肺
E.肾
