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

（2009年辽宁松源市中考题）“上边毛，上边毛，中间一颗黑葡萄”这个谜语的谜底是眼睛，其中“黑葡萄”指的是（　　）

A．眼球

B．虹膜

C．角膜

D．巩膜