问题补充：
Mandela, having devoted all his life to the freedom of South African Blacks, is a real fighter for us to.
A. live up to
B. come up to
C. make up to
D. look up to
答案：
A. live up to
B. come up to
C. make up to
(答案→)D. look up to
解析：A. live up to不辜负 B. come up to达到 C. make up to接近，补足 D. look up to尊敬；句意：曼德拉将自己的一生都致力于南非黑人的自由运动，对于我们来说他是一个值得尊敬的斗士。故选D
