营业服务应做到“四个有声”：来有迎声，去有送声，（）。
A.问有答声
B.说话有笑声
C.收付款有唱声
D.问有回声
参考答案：A, C
When people talk about splendid cities in China, probably the first______ comes into their minds is
Beijing. [ ]
A. one
B. that
C. city
D. which
常用的开关电器有哪些？他们各有什么功能？
