单项选择题
A．the present one is refused by the patient B．the patient complains about the present one C．the present one proves to be ineffective D．the patient is found unwilling to cooperate
A．is certain to succeed B．is successful in his studies C．is considered an educated person D．can grasp any problem
A．the lack of official support B．its high cost C．its failure to help increase production D．the lack of financial support