She is used to ________ in the room which ________ to keep books．
A.living; usedB.live; was usedC.live; usedD.living; was used在线课程D
解析：
be used to(doing)sth．“习惯于(做)某事”，to是介词，其后接名词、代词或动名词．be used to do sth．是use的被动结构，意思是“被用来做某事”，主语是动作的承受者．used to do sth．“过去常常做某事”，意指现在已经没有这种习惯了．