24.  _____ any biscuits that morning, we had nothing to eat.

A．Not baking

B．Not having baked

C．Not being baked

D．Not having been baked

服务员对急躁型顾客提拱服务时要（）。

A、行动迅速、语言简练

B、耐心细致、温文尔雅

C、主要热情、细心观察

D、举止端庄、不厌其烦