题目

________ of my parents are workers．They are working in the school． A．Each                      B．All                          C．None                     D．Both 答案：D16．关于溶液的说法正确的是（　　）A．溶液都是无色透明的B．硝酸铵溶于水放出热量C．均一、稳定的液体都是溶液D．饱和溶液不一定是浓溶液