Amotherwantedtoencourage（鼓励）hersontoplaythepiano．Sheboughtticketstotheconcert（演奏会）ofagreatpianist．Whentheyarrivedatthetheater，themotherfoundafriend．Shestoppedtotalktoherfriendandhersonran

　　A mother wanted to encourage（鼓励）her son to play the piano．She bought tickets to the concert（演奏会）of a great pianist．When they arrived at the theater，the mother found a friend．She stopped to talk to her friend and her son ran off．

　　At eight o'clock the lights began to dim（变暗）and the concert was set to start．The mother began to look for the boy．Then，she saw her 6-year-old son on stage．He was playing Twinkle，Twinkle little star．

　　The mother was very surprised．Before she could get her son back，the famous pianist himself was on the stage and quickly moved to the piano．

　　"Don't stop．Keep playing，"he said kindly to the boy．The great pianist reached down with his left hand and began filling in the bass（低部）of the song．Soon，his right arm reached around the other side and played a beautiful piece of music．Together，the two excited people with their beautiful music．

　　In all of our lives，we receive helping hands，some we notice，some we don't．We also have lots"chant to give helping hands，sometimes we want people to know，sometimes we don't．Little

　　of what we al l get comes without others'help．What we receive we should give back．

　　51．The mother took her son to the piano concert because___．

　　A．her friend sent them two tickets

　　B．the pianist invited them there

　　C．she wanted to develop his interest in piano

　　D．her son liked the pianist very much

　　52．What was the little boy doing when his mother saw him？___

　　A．He was listening to concert in his seat．

　　B．He was talking to his friend．

　　C．He was playing a piece of music．

　　D．He was learning from the famous pianist．

　　53．What was the mother's feeling when she found her son playing on stage？___

　　A．She was proud of her son．

　　B．She couldn't believe her eyes．

　　C．She was interested in the music．

　　D．She held back her anger．

　　54．What did the pianist ask the boy to