You can have as many controls as necessary, But they must remain equal at all times in order to get the most accurate results
        
             
        
        
        
Answ burh i dont even know 
Explanation: i dont even know this 
 
        
             
        
        
        
Answer:
CaO + SO 3 → CaSO. 4
This is an acid-base reaction (neutralization): CaO is a base, SO 3 is an acid.