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

A. performing                  

B. performed    

C. to be performed                

D. being performed

胼胝体发育不良的诊断要点是()

A．双侧脑室前角及体部间距增宽，三脑室上移

B．三脑室扩大

C．合并多小脑回

D．合并Chiari畸形

E．合并Dandy-Walker综合征