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hoangtuvip31
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
1/ co' 5 dd :NaHSO4,KHSO3,Na2SO3,Mg(HC03)2,Ba(HCO3)2.trinh` bay` cach' nha^n. bik tung` dd tre^n(chi? dung` the^m phuong phap' dun)
vietkey hong? em xin loi~
vietkey hong? em xin loi~