题目

—That's the third time he's won the award in this field． —Yes．He ______ his maximum potential in the past decade． A．explored                                                    B．is exploring C．has been exploring                                    D．had explored 答案：C下列大小顺序排列完全正确的组合是A．气态氢化物的稳定性：HF＞NH3＞PH3＞H2SB．沸点：苯酚＞CH3OH＞HCHO＞CH3COOHC．离子半径：S2-＞O2-＞F－D．相同温度、相同浓度溶液中水的电离程度：NH4Cl＞CH3COOH＞HCl＞Ba(OH)2