军用牌照的货车应查验下列哪些证件（），证件齐全、相符，免费放行。

A、行驶证

B、驾驶证

C、军人证件

D、派车单

Sally, a shy girl, never speaks in public _______ she is asked to, never!

A．until

B．unless

C．even though

D．as though