统计的过程也是对客观事物的认识过程,从统计的认识对象看,其特点主要有( )。
A.数量性
B.差异性
C.总体性
D.具体性
E.变异性
参考答案:A,C,D,E
“65、69、72、87、89”这组数据的算术平均数是()。
The ()theory of language learning was initiated by the psychologist Skinner, who applied Watson and Raynor’s theory of conditioning to the way humans acquire languages.