题目

After the earthquake, almost all the windows are ____. A. break                                    B. broke                           C. broken               D. breaking 答案：C15．请用化学用语（化学符号）填空（1）三个氦原子3He（2）两个氯离子2Cl-（3）地壳中含量最多金属元素Al（4）锰酸钾K2MnO4．