题目

施用NaNO3后，土壤溶液将会发生的变化是 A．OH－浓度上升，NO浓度下降            B．H＋和Na+浓度上升 C．Na+浓度上升，NO浓度下降             D．OH－和NO的浓度下降 答案：A 解析: 根细胞吸收NO比Na+多，经交换吸附置换下来的HCO多，HCO+H2O→H2CO3+OH-，从而OH-的浓度上升。13．About 90 percent of the equipment presented by the administration，as well as the facilities of our own，      ______made good use of in teaching．A．haveB．hasC．have beenD．has been