— Would you mind my sitting here, Sir?     

— _____. It's for my wife. [ ]

A. Not at all

B. Certainly not

C. I'm afraid you can't

D. All right

脊柱外伤造成脊髓休克，是由于

A．脊髓神经细胞遭受震荡，产生暂时性功能抑制，发生传导障碍

B．骨折片刺入脊髓

C．因脊髓受血肿等压迫

D．外伤后脊髓神经细胞遭破坏

E．脊髓上、下行神经传导束断裂