— You haven’t said a word about my new coat, Brenda. Do you like it?

— I’ m sorry I ＿＿ anything about it sooner. I certainly think it’s pretty on you.

A．wasn’t saying

B．don’t say

C．won’t say

D．didn’t say

如图所示，烧杯中质量相等的铁圈和银圈用一根绝缘细丝相连，再两者之间，同样用一根绝缘细丝吊住，并使其在水中保持平衡，然后小心地从烧杯中央滴入CuSO₄溶液，反应一段时间后，观察铁圈、银圈的现象分别为 _________ ．试写出有关的化学方程式 _________