Any packet __   properly will not be accepted by the post office．

A．not to address

B．not being addressed

C．not addressed

D．not having addressed

承运人或其代理人签发给托运人。证明货物已经收到，并保证在目的港地凭以交付货物的书面凭证称为()。

A．提单

B．提货单

C．发货单

D．收货单