Questions 14 to 17 are based on the following passage.At the end of the passage, you will be given 20 seconds to answer the questions.
Now, listen to the passage. Usually waiters and waitresses expect their tip to beA．25 % of the bill. B．15 % of the bill. C．50% of the bill. D．20% of the bill.
试题查看
参考答案： 
答案解析