As a ______actor, he can perform, sing, dance and play several kinds of musical instruments.

A．keep fit by going in for physical activities
B．keep mentally active by challenging their brains
C．maintain mental alertness through specific training
D．maintain a balance between individual and group activities

A．who can remember large amounts of information
B．who are highly intelligent
C．whose minds are alert and receptive
D．who are good at recognizing different sounds