Questions 14 to 16 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.
Now, listen to the passage.
About ______ American homes have the habit of keeping pets.

A．they provide a good service and they deserve the tips
B．without enough tips they can’t make a living easily
C．only in this way can they make up the difference between others
D．their basic hourly pay is relatively rather low

A．They are always very crowded and not safe.
B．Drinks are paid when you get them.
C．There are always people who sneak out without paying the bill.
D．Unexpected events usually occur after the costumers got drunk.