There was a little boy who got angry easily. His father gave him a bag of nails(钉子) and told him that every 1he got angry, to drive a nail into the back wall. The first day the boy had237 nails into the wall. Then he put fewer and fewer nails. He found it was3to be not angry than to drive those 4into the wall. Finally the day came when the boy didn't get 5at all. He told his father about it and the father suggested that the boy now pull out one nail for each day that he was able to be not angry. The days 6and the young boy was finally able to tell his father that 7nails were gone. The father took his son by the hand and led him to the8. He said, "You have done 9, my son, but look at the holes in the wall. The wall will 10be the same. When you say things 11, they leave a scar(伤疤) just like this one. You 12put a knife in a man and draw it out. It won't matter 13you say I'm sorry, the wound(伤口) is still there. A mental hurt is as bad as a physical one. Friends are a very rare jewel, indeed. They make you 14and encourage you to succeed. They lend an ear, they share a word of praise, and they always15 to open their hearts to us.

1He is the only student______ I've ever met ______ could answer this question .