正式的组织通常都具有目的性、整体性和（）的基本特征。
A、相关性、静态性
B、相联性、静态性
C、相关性、动态性
D、相联性、动态性
参考答案：C
Some doctors were sent t?the front where medical workers were ＿＿＿.
A. in great need B. in great need of . needed great D. needed in
模拟信号的特点。
