题目

连词成句【1】to buy some she wants bananas【2】how play Jim does often football【3】are interested music we in【4】doing boy his the is homework【5】there the aren’t any in birds tree 答案：【答案】【1】She wants to buy some bananas.【2】How often does Jim play football?【3】We are interested in music./ Are we interested in music?【4】The boy is doing his homework. \ Is the boy doing his homework?【5】There aren’t any birds in the tree.【解析】【1】句意：她想买些香蕉。结合提示词，分析句子结构和句意，可知本句是主谓宾结构的陈aXn－和bYm＋是由短周期元素形成的最简单离子，已知Xn－比Ym＋多两个电子层，下列说法中正确的是（　　）  A.X只能是第三周期元素                B.Y不可能是第二周期元素 C.Y一定是氢元素                      D．a－b＋n＋m等于10或16