A、Tips are part of their salary. B、Tips mean good service. C、Tips mean lots of money. D、Tips mean the price of the boss. A因果关系题。

A lot of people don’t like to give waiters extra money — a tip, but maybe those people don’t understand about the waitresses and waiters. You see, we get very low wages, most of the time less than the minimum wage. We count on the tips as part of our salary. If waiters and waitresses didn’t get tips, they wouldn’t get enough money to live. (33) People ask me, "What is a good tip?" I like to get 15% of the bill. So if a customer has to pay $ 20.00 for his dinner, I like to get about $ 3.00 for a tip. Sometimes I expect 20% if I did a lot of work for the customer. (34) For example, if I got him a special kind of food or recipe from the chef. But do you know something? Very often it’s the person you work the most for who gives you the smallest tips. But to tell the truth, I do pretty well with the tips. I am a friendly person, so people like me. They talk to me during their meal and leave me a good tip. Of course some people prefer a quiet waitress and every once in a while I get some pretty small tips or no tip at all. Once I looked up "tipping" in a dictionary. It says that the letters in the word "tip" stand for "to insure promptness". In other words, to make sure we do things right away. The dictionary says that no one knows if that is the real meaning of "tip", but it makes sense to me. If we know a regular customer is a good tipper, then we make sure he gets good service. (35)
33. Why are tips so important to waiters or waitresses?
34. How can a waiter get more tips?
35. What does the passage mean to imply?