问题 单项选择题

两种证券组成的投资组合,当证券间的相关系数小于1时,下列关于分散化投资的表述中,不正确的是( )。

A.分散化投资发生必然伴随投资组合机会曲线的弯曲

B.投资组合报酬率标准差小于各证券报酬率标准差的加权平均数

C.两种证券报酬率的变化方向和比例相同

D.其投资组合的机会集是一条曲线

答案

参考答案:C

解析: 两种证券组成的投资组合的机会集是一条曲线。只要两种证券的相关系数小于1,它们组成的投资组合就具有分散风险的作用,机会集曲线就会弯曲,投资组合报酬率标准差就会小于各证券报酬率标准差的加权平均数。只有相关系数等于1时,两种证券收益率的变化方向和比例才是相等的,所以C错误。

完形填空

No air means death. There is air around us  36 we can’t see it. Air is everywhere and it gives   37  to every living thing. We can’t live  38  it. Bad air makes people ill. We must have fresh air to keep us  39 .

In the city there are a lot of people and there are too many  40  running on the road. The gas which the car sends out is made up of(组成) bad gases. Every day we  41  it in and        out. This makes us feel sick. There are many  42 , too. From the chimneys(烟囱) of these factories, we  43  get the smoke in black color. This kind of smoke is  44 to our health. So in order to keep us healthy, we have to go out to the   45  to breathe more fresh air. Or we can go up hills to get more fresh air.

小题1:A. because            B. though              C. so

小题2:A. life               B. name              C. pleasure

小题3:A. with               B. without         C. below

小题4:A. quiet              B. tall          C. healthy

小题5:A. dogs           B. trains        C. cars

小题6:A. breathe            B. draw          C. bring

小题7:A. animals            B. people          C. factories

小题8:A. usually          B. never             C. seldom

小题9:A. helpful          B. dangerous       C. necessary

小题10:A. office          B. city            C. Countryside

单项选择题