人的生命独特性突出表现在   [    ]

A．个性品质丰富多彩                    

B．人类的生命最具有智慧

C．人生道路多种多样                    

D．实现人生价值途径多样

They won't give up _____ they have failed several times.   [ ]

A. as a result        

B. in order that      

C. although        

D. since