—Excuse me could you tell me a book about music? —Sure. They are on the second floor.A.

问题补充：

—Excuse me, could you tell me a book about music?

—Sure. They are on the second floor.

A. where can I buy B. where I can buy C. when I can buy D when I can buy

答案：

解析：考查宾语从句。句意：对不起，你能告诉我在哪能买到音乐方面的书籍吗? 可以，就在二楼。Tell 后面跟着一个宾语从句，由特殊疑问词引导用正常语序，故排除A，D项。根据下方提到 They are on the second floor.可知就地点进行提问，所以选B项。