题目

阅读下面材料，根据其内容和所给段落开头语续写两段，使之构成一篇完整的短文。AtDana's yard sale, Tim chose a baseball from the toys spread on the card tableand asked about the price. Dana told him everything was a quarter except Nezumi,a cotton toy rat. It was grey with some cotton sticking out from the hole wherean ear had been torn off. Nezumiis extra special, so he is ten dollars. He needs a safe new home, Danasighed. Tim laughed, saying he didn't have ten dollars. Dana laughed too andgave Nezumi to Tim as a free gift because he was her friend. When Tim wh4．设NA为阿伏加德罗常数，则下列说法正确的是（　　）A．一定条件下，2.3g Na完全与O2反应生成3.6g产物时得到的电子数为0.1NAB．1L 0.1mol醋酸溶液中所含分子数少于0.1NAC．水分子中1mol羟基含有的电子总数为9NAD．1 mol H2O2含有极性共价键键数为NA，含有非极性共价键为键数2NA