单项选择题 理财师小王学习了投资组合理论后,与同事讨论中提出:①.可以利用两种相关系数为-1的资产构造出无风险资产②.协方差不可能小于0小王的以上说法是否正确()A ①正确②正确B ①不正确②不正确C ①不正确②正确D ①正确②不正确

单项选择题 Please select a word to replace the underlined one.What they found out is so important that the university decided to make changes to its policies.A.motionB.modificationC.moralizationD.modernization

单项选择题 填入下面横线处，与上文衔接最恰当的一项是()