用均数和标准差可以全面描述下列哪种资料的分布特征()
A.正偏态资料
B.负偏态资料
C.抗体滴度资料
D.正态分布资料
E.任何分布的资料
参考答案:D
商朝的统治区域是[ ]
A.东到大海,西到新疆
B.东到海滨,西到陕西西部
C.东到山东,西到山西西部
D.东到大海,西到甘肃
In your project, if the benefit cost ratio is greater than 1, it means that______.
A.the ratio of profits to cost is greater than 1
B.the ratio of revenue to cost is greater than 1
C.you should select this project from all other competing alternatives
D.none of the above