问题补充：
We have two rooms , but I can’t decide .
A. to live; to choose which one
B. lived ; choose which one
C. to live in ; which one to choose
D. live ; which one
答案：
A. to live; to choose which one
B. lived ; choose which one
(答案→)C. to live in ; which one to choose
D. live ; which one
解析：句意：我有两个房间可以居住，但是我不知道选择那个。动词不定式做后置定语时和被修饰词之间存在逻辑上的动宾关系所以动词不定式后的介词不要丢掉。疑问词+动词不定式，可以做宾语。根据句意及结构，故选C。
