15. A group of children ______ around the old man, listening to him telling the story and they ______ when it came to something really exciting.

A．were gathered; held their breaths

B．gathered; held their breath

C．gathered; held their breaths

D．were gathered; held their breath

目前，我国的行政单位会计采用的会计基础主要是（）。

A．权责发生制

B．应收应付制

C．收付实现制

D．统收统支制