In paragraph 3，the author gave the dental office example to show that________A、eye contact is essential in communication
B、acknowledging the customer is very important
C、good first impression helps a lot in doing business
D、smiling at the customer helps form a good relationship
【正确答案】：B
【题目解析】： 细节判断题。第三段提到作者在牙医办公室的不愉快经历。作者走进牙医办公室在前台站了至少一分钟。前台工作人员明知他在那里却不打招呼。她的迟钝反应令作者很不爽。可见，牙医办公室的例子是为了进一步说明招呼客人的重要性。B是正确答案。