A：甲图是氟离子的结构示意图
B：乙图中元素的原子核外有18个电子
C：丁图表示钠元素显正一价
D：若“○”表示1个氧原子，则丙图表示两个氧原子
—I don't know if it ____ tomorrow.
—Well, if it ____, I won't go out with you.
—“Les Miserables” is a wonderful film.—_______. I've never seen such a moving film before.
人类进入文明时代的标志是 ( )
