酸性镀锡液配制时应将硫酸亚锡溶于热的硫酸溶液中，边加边搅拌，使其完全溶解后再加入到镀槽中。
参考答案：对
正方形具有而菱形不一定具有的性质是 [ ]
A、对角线互相平分
B、对角线相等
C、对角线平分一组对角
D、对角线互相垂直
------It was fine yesterday.
-------________.And very day for fishing,isn’t it?
A．So it was
B．So it is
C．So was it
D．So is it
