A customer ordered a cup of coffee in a restaurant！ The waiter served the coffee. The customer found a fly in the coffee. He called the waiter.
　　Customer： How do I drink this coffee！
　　Waiter： Don’t you know how to drink a coffee？
　　Customer： Waiter， see， there is a fly in my coffee.
　　Waiter： Oh yes sir， you are right！ There is a fly in your coffee.
　　Customer： Waiter， I said， there is a fly in MMY coffee （He stressed the word MY）
　　Waiter： Oh don’t worry， sir， the fly won’t drink much！
　　Customer： Waiter， it is swimming in my coffee.
　　Waiter： Sir， do you want me to get a lifeguard for the fly？
　　（Annoyed） Customer： the fly dead， it’s hard to stand！
　　Waiter： I guess， it doesn’t know how to swim properly.
　　Customer： How do I drink this coffee？
　　Waiter： Don’t you know how to drink？ I will teach you！
　　He drank the coffee！ And said， this is how you should drink a coffee.
　　（Question： What is the customer angry for？ .）