The story of ________ American South will be one of hope and success with some signs that ________ new, different South is coming out of its dark past.

A．the; a

B．an; a

C．不填; a

D．an; the

论述盾构刀盘轴承失效，刀盘无法转动，失去切削功能的原因及预防措施。