Questions 6 and 7 are based on the following news. At the end o f the news item, you will be given 10 seconds to answer each of the two questions. Now listen to the news. The staff who work in public places would favor the ban because ______.
A．they don’t have to inhale foul air. B．they don’t have to serve smokers. C．they will get more tip from non smokers. D．there will be a rise on their salaries.