B Recently,as I watched my son Nathan play basketball for his high school team,I was starting to feel sorry for myself and for him.His team was facing adversity(逆境)on the court and he was playing in a hostile environment-it was the opponent's home gym filled with their supporters,and Nathan's team was trailing(落后)for three quarters of the game.As for me,I had been dismissed from my job earlier in the day. During my drive home,I kept telling myself that I will find work again in a short time-I am confident in my experience and abilities.This is the same belief that I tried to instill in my son. The basketball game entered the fourth quarter with Nathan's team still trailing.I saw the determination on his,as well as his teammates'faces as they fought back to not only tie the game(平局),but then go ahead by three points.Then,a player from the other team made an unbelievable shot to tie the game up again.With a tie game and seconds on the clock,Nathan found himself with the ball and with skill and confidence,he proceeded to make the basket with a defender hanging all over him.The other player was called for a foul(犯规). As Nathan stood at the foul line preparing for a shot that would put his team up by three points,I saw the focus and determination on his face,there was no room for self doubt.Nathan was able to turn out all the distractions and nail the free throw with such skill,it was as if he had done it a thousand times. As I sat there,my heart bursting with pride,it dawned on me.I had taught him perseverance in the face of adversity,and he had just taught me the same lesson.That brief moment of self-doubt and feeling sorry for myself was blown away by the actions of my son on the basketball court.He will play in the finals,but it doesn't matter if he wins or loses,at this moment,we both won. 6. What does the underlined phrase"tune out"in Paragraph 4 mean?______