题目

短文填空  根据短文内容及首字母提示，补全空格内单词，使短文完整、通顺。 Do you like taking music lessons? A study shows music lessons can make children have b   1   memories(记忆力) than others. The Canadian study shows that a   2  one year of training in music, c  3  could get better grades(分数) in a memory test than others. There were two groups of children aged b   4    14 and 16 in the study. One group of children took music lessons outside school, and the o   5   group didn’t take any lessons. In one year, they took four te某元素原子的最外层只有2个电子，则该元素  (　    )A．一定是ⅡA族元素B．—定是金属元素C．一定是正二价元素D．可能是金属元素，也可能不是金属元素