What they discovered was nothing less than a new source of energy.（）

A．Nanto is the first city to experiment with using robots to help care for the elder citizens.
B．Paro can respond to human voices and loving touches.
C．Companion robots have the ability to eat.
D．Aibo can understand thoughts and feelings of human being.

A．It can adequately impact the health and well-being of the elderly positively.
B．It stimulates brain activity of patients with dementia.
C．It has little effect on lowering stress, elevating moods and decreasing depression.
D．It only positively affected the patients.