No matter how frequently＿＿，the works of Beethoven still attract people all over the world.

A．performed

B．performing

C．to be performed

D．being performed

体现尊重原则的是（）

A.杜绝对病人的有意伤害

B.选择受益最大、损伤最小的治疗方案

C.患者及家属无法实行知情同意时，医生可以行使家长权

D.对病人一视同仁

E.合理筛选肾脏移植受术者