题目

Three years ago, when Steve Baker's stepson was stationed （驻军）in Iraq, the soldier received a birthday present from home．It was a guitar, and it was a hit．Word spread, and his friends began asking for instruments．  Steve and his wife, Barb, are longtime musicians who believe in music's power to comfort and inspire．With music, for just a minute, you're back home, Steve says． The Bakers organized a silent auction （拍卖）at the local American Legion and raised $900． The Bakers sent off 22 guitars three days later． They named their effort Operation Happy Note, and in thXY型性别决定的生物，雄性个体产生的精子中A.性染色体都只有Y染色体B.性染色体都有X和YC.性染色体都只有X染色体D.性染色体有X或Y