下列各组离子，能在水溶液中大量共存的是（　　）

A．Na⁺   H⁺   Cl^- HCO₃^-

B．K⁺ Na⁺  OH^- AlO₂^-

C．K⁺ Ca²⁺  OH^-  CO₃^2-

D．Fe³⁺  OH^- Br^- NO₃^-

________ you are good friends, you must know each other very well. [      ]

A. Even though  

B. Unless

C. Now that  

D. Before