We would like to thank the founder of our library, without ________ help none of this would have been possible.

A．which

B．whom

C．whose

D．that

可转换债券是指其持有者可以在一定时期内按一定比例或价格将之转换成一定数量的（）的债券。

A.基金

B.优先股

C.另一种证券

D.B股