题型:选择题 短周期元素aA2+、bB+、cC3-、dD-都具有相同电子层结构,则下列叙述正确的是 )A.原子半径A>B>D>CB.原子序数D>C>B>AC.离子半径C>D>B>AD.单质还原性A>B>D>C 查看答案
题型:单项选择题 We should always bear in mind that ______ decisions often result in serious consequences.A. urgent B. instant C. prompt D. hasty 查看答案