Though every parent admits that reading contributes to        better mind of their child, yet let’s face it, who has got       time?

A．a; the

B．a; /

C．the; the

D．the; /

目前，我国证券交易所的证券回购券种主要是（　　）。

A．国债

B．股票

C．可转换债券

D．基金证券