题目

下列说法中错误的是（） A . 某原子K层上只有1个电子 B . 某原子M层上电子数为L层上电子数的4倍 C . 某离子M层上和L层上的电子数均为K层的4倍 D . 某离子的核电荷数与最外层电子数相等 答案：BScarcely ________ ourselves in the theatre when the curtain ______ up.A．had we seated; went B．we had seated; wentC．seated; had goneD．did we seated; had gone