—It's next to the library.

A.What'sB.Where'sC.When's

【答案】B

【解析】

句意：—打扰一下。音乐教室在_____？—在图书馆旁边。A. What's是什么，B. Where's是哪里，C. When's是何时，答句回答地点，故选B。