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。