The cartoons made by the artists sell best, but several years ago no one could imagine how great a role he _____

in the field. [ ]

A. was playing

B. was to play

C. had played

D. played

有助于周围神经病诊断的检查有（）

A.肌电图

B.脑电图

C.脑干诱发电位

D.神经传导速度

E.H反射