---Which floor do you live ?---The first floor. I live Room 112.A. in / onB. on / onC. on

问题补充：

---Which floor do you live ?

---The first floor. I live Room 112.

A. in / on

B. on / on

C. on / in

D. in / in

答案：

A. in / on

B. on / on

(答案→)C. on / in

D. in / in

解析：根据语境可知此句考查两个固定短语live in和live on。前者表示住在某一层楼，后者表示住在某个房间，故选C。