下列数字为几种元素的核电荷数,其中原子核外最外层电子数最多的是 [ ]
A.8
B.14
C.20
D.34
AD
When she ______ back tomorrow, I’ll tell her all about the news.
A.will come
B.comes
C.had come
D.is coming
过滤是变压器油脱除()的最有效手段
A.水分
B.固体杂质
C.酸性杂质
D.气体