A. Ask the operator to call you back later. B. Make a "person-to-person" call. C. Call back outside office hours. D. Walt and call again when the line is free. 参考答案:A 答案解析:[解析] 事实细节题。从文章第二段最后一句话可知,If the international line is busy,you can reserve(留下)a call,explain the num