【单选题】下列表述中不正确的是( )。
A.
只要投资比例不变,投资组合中各项资产的期望收益率不变,则投资组合的期望收益率就不变
B.
投资组合的风险不会高于所有单个资产中的最高风险
C.
投资组合的收益率不会低于所有单个资产中的最低收益率
D.
当两项资产之间构成的投资组合能分散风险时,其相关系数一定是负值
【单选题】下列说法中,正确的是( )
A.
频率分布直方图中各小长方形的面积不等于相应各组的频率
C.
数据2,3,4,5的方差是数据4,6,8,10的方差的一半
【简答题】A.He enjoys writing home every week. B.He never fails to write home once a week now. C.He doesn't write home once a week now. D.He has been asked to write home every week.
【单选题】He plays basketball every day. And now he is playing piano at home. [ ]
【简答题】句型转换。 1. He goes home by bus every day.(同义句) He _____ _____ _____ home every day. 2. Andy can put the football behind the door. (划线提问) _____ _____ Andy put the football? 3. They have five lessons e...
【判断题】刀尖在刀刃的最高位置时,刃倾角为正.____ 四名词解释:
【简答题】He said that he goes home to see his parents every______week. A.another B.the second C.two D.other
【单选题】共模抑制比 K CMR 是 ( )
C.
差模放大倍数与共模放大倍数 ( 绝对值 ) 之比
D.
交流放大倍数与直流放大倍数 ( 绝对值 ) 之比