Does your new secretary  ____ short hand?

A．know to take

B．know how to take

C．know how take

D．know how taking

为了满足投资者中途抽回资金、实现变现的需要，（）一般在基金资产中保持一定比例的现金。

A．封闭式基金 

B．开放式基金 

C．国债基金 

D．股票基金