He has ______ his fortune many times since he began to deal in second-hand car business. [ ]

A. added to    

B. created      

C. multiplied  

D. risen

某工厂排放的工业废水中可能含有K⁺、Ag⁺、NH₄⁺、Mg²⁺、SO₄^2-、Cl^-、NO₃^-、HCO₃^-等离子．经检测废水呈明显的碱性，则可确定该厂废水中肯定不含有的离子组合是（　　）

A．Ag⁺、K⁺、NO₃^-、HCO₃^-

B．K⁺、NH₄⁺、NO₃^-、SO₄^2-

C．Ag⁺、NH₄⁺、Mg²⁺、HCO₃^-

D．K⁺、Mg²⁺、SO₄^2-、Cl^-