A:Cl﹣、Fe3+
B:HCO3﹣、Al3+
C:Ba2+、SO42﹣
D:Na+、SO42﹣
影响平行板电容器电容的因素有很多,探究中需采用控制变量法。如图,充满电的两个极板所带电荷量不变,两极板正对面积为S,极板间的距离为d,静电计指针偏角为θ。实验中,改变电容器的结构,关于可能看到的现象,下列说法正确的是( )
His wife, to whom he _____ for 20 years, died of cancer last Thursday. ( )