硬脊膜外隙注射类固醇治疗腰椎间盘突出症的作用机制是：（）

A.使椎间盘复位

B.消除神经根的炎症和肿胀

C.营养椎间盘髓核

D.通过脊髓后角起作用

E.使椎间盘溶解

Was it on a lonely island ________ he was saved one month after the boat went down？(2011·四川)

A．where

B．that

C．which

D．what