A．What does the author intend to illustrate with the example of the Harts
B．The difficulty of paying the tuition.
C．The increasing tuition in the university.
D．The far-sight of the parents.
E．The promising future of Katie.

A．Because they want to make the attendants work faster.
B．Because they think fast music can make people eat more.
C．Because hamburgers will become more popular by this way.
D．Because they hope customers will spend less time on eating than before.