A：向某溶液中加入稀盐酸，产生的气体通入足量澄清石灰水，石灰水变浑浊，该溶液一定是碳酸盐溶液
B：用洁净铂丝蘸取少量某溶液进行焰色反应，火焰呈黄色，该溶液一定是钠盐溶液
C：向某溶液中滴加KSCN 溶液，溶液不变色，滴加氯水后溶液显红色，该溶液中一定含Fe2+
D：将某气体通入溴水中，溴水颜色褪去，该气体一定是SO2
- Are all the students from in your class?
- No, there are only 3 in our class. The others are from other countries.
