题目

X、Y、X均为短周期元素。已知X元素的某种原子核内无中子，Y元素的原子核外最 外层电子数是其次外层电子数的2倍，Z元素是地壳中含量最丰富的元素。有下列含该 三种元素的化学式：①X2Y2Z2 ②X2YZ3 ③X2YZ2 ④X6Y2Z2 ⑤X3YZ4 ⑥XYZ3，其中可 能存在的是                                                                                                                A．②     B．②④  C．②⑤⑥   �---Did you go to Lucy’s birthday party last night?---Yes, I did. _______.A. So did Tom B. So Tom didC. Tom did so D. Tom went to