—Where _____ Mary have put the empty bottles?

— She _____ them away. They must be somewhere.

A．can; can’t have thrown

B．must; needn’t

C．must; must have thrown

D．can; mustn’t have thrown

证券登记结算机构应该设立( )。

A．交易结算保证金

B．员工奖励基金

C．职工培训基金

D．结算风险基金