题目

在一定温度下，向饱和的烧碱溶液中放入一定量的Na2O2，充分反应后恢复到原来的温度。下列说法中正确的是（    ）        A．溶液中OH-总数不变，有O2放出        B．溶液中Na+的物质的量浓度增大，有O2放出        C．溶液中Na+总数减少，有O2放出        D．溶液pH增大，有O2放出 答案：C _______of the household rubbish___recycled or reused since the new technology was applied. A．Three-fourth; has                                   B．Three-fourths; have C．Three-fourths; has been                      D．Three-fourth; have been