题目

铊盐与氰化钾被列为A级危险品，铊（Tl）与铝同主族，原子序数为81，Tl3+与Ag在酸性介质中发生反应：Tl3+ + 2Ag =Tl+ +2Ag+ 且已知  Ag+ +Fe2+ = Ag + Fe3+ 则下列推断正确的是（    ）        A．Tl+ 最外层有3个电子  B．氧化性：Tl3+ >Ag+>Fe3+        C．还原性：Tl+ >Ag           D．铊位于第五周期IIIA族—How long has Mary _________?—Since 2012.A. been to Zheng Zhou B. become a policewomanC. joined the art Club D. taught English in this school