The traditional friendship between our two peoples ____ ancient times. A.is dated back to B.dates atC.dates back to D.dated from 答案:C有A、B、C、D四种短周期元素,A、B元素的阳离子和C、D元素的阴离子都具有相同的电子层结构,且A单质的还原性比B单质的还原性强,C的阴离子所带负电荷比D的阴离子所带负电荷多,则A、B、C、D的原子序数大小关系是( )A.B>A>C>DB.C>B>A>DC.A>B>C>DD.B>A>D>C