Why is tourism a mixed blessing __________

A．Because they want to know something that the others don’t know.
B．Because they understand the importance of the course.
C．Because they can learn more in this course about their professionals.
D．Because they will be paid more on their present jobs.

A．Take a walk and have some food.
B．Study and get some exercise.
C．Borrow some notes from their classmates.
D．Go on for skiing.