What determines whether an animal is sleeping or just resting______.

A．Because it is a personal and economic problem as well as a social one.
B．Because it is a totally personal problem.
C．Because it is a huge burden on economics.
D．Because it is social problem.

A．The computer class will be held tomorrow morning.
B．She will give the man the class schedule in the afternoon.
C．She can’t give the man the information he wants today.
D．She doesn’t know how to get the class schedule.