Those who ____ in ____ compositions, please hand them in this afternoon. [ ]

A. hasn't handed; his

B. haven't handed; their

C. has handed; their

D. have handed; his

一般情况下，外存储器中存储的信息，在断电后

A．局部丢失

B．大部分丢失

C．全部丢失

D．不会丢失