题目

Even on a cold day he prefers ______ out to play football ______at home．        A．going;rather stay            B．going;to staying        C．to go;rather than staying  D．to do;rather than to stay 答案：B 解析: 略密度为0.910 g·cm－3的氨水，质量分数为25.0%，该氨水用等体积的水稀释后，所得溶液的质量分数为A．等于12.5% B．大于12.5% C．小于12.5% D．无法确定