Our lab is on the third of a six— building.A. floor; storyB. floors; storiesC. ground; fl

问题补充：

Our lab is on the third of a six— building.

A. floor; story

B. floors; stories

C. ground; flat

D. apartment; ground

答案：

(答案→)A. floor; story

B. floors; stories

C. ground; flat

D. apartment; ground

解析：考查名词辨析。句意：我们的实验室在一幢6层楼房的第3层。由此可知前空指建筑物的“楼层”；后空指指层与层之间的空间，故答案为A符合。