Sydney is certain to be able to provide ways of filling the leisure hours of each overseas student both outside and ______.

A．He forgot to assign homework to his students.
B．He has no time to give the class.
C．He is ill, but he has a class today.
D．He has forgotten to take his key and can’t get into his office.

A．The opera will not be performed.
B．All the tickets for the opera were sold.
C．They are going to watch the opera.
D．They don’t have much interest in the opera.