According to the passage, which of the following statements is true?
A.
The Chinese people have to give tips in western countries.
B.
The westerners don't have to give high tips in their own country.
C.
Barbers, hotel bellboys and all sorts of other people can earn a living if they are not tipped.
D.
Tipping varies from place to place, generally in the area of 20% of your bill.