题目

Being positive is very important.So I often__36__my son to be positive.But one day I was caught not__37__what I often tell him to do. My son is 7 years old and he was__38__a show to be put on at his school.He was playing the role of an angel.On the evening before the show，he asked me，“Mom，can we__39__angels？” As usual，I seized (抓住) the__40__to teach him to be positive and I said，“Yes，__41__only those who are perfect，and think and talk positively can.” He asked，“You must have seen them then？” I was__42__for a few seconds，not knowing what to say.I w用毛皮摩擦橡胶棒，橡胶棒会带上负电荷，这是由于（ ）A．毛皮束缚电子的能力比较弱B．橡胶棒的正电荷转移到毛皮上C．摩擦过程中创造了负电荷D．毛皮上本来有多余的负电荷