[单项选择]All of us ought to be able to brace ourselves for the predictable challenges and set backs that crop up in our everyday life. If we (47) that life won’’t be perfect, we will be able to avoid that (48) to quit. But even if you are strong enough to persist the obstacle course of life and work, sometimes you will encounter an adverse event that will (49) knock you on your back. A quick look at the history will tell you that history is full of example of men and women who (50) greatness despite facing hurdles. Moses was a stutterer, yet he was (51) on to be the voice of God and led the ancient Hebrews to the Graceland. Abraham Lincoln overcame a difficult childhood, depression, the death of two sons, and (52) ridicule during the Civil War to become our greatest president ever. Hellen Keller made an (53) on the world despite being deaf, dumb, and blind from an early age. There are (54) examples. These were people who not only looked adversity in the face but learned