Overtillage can increase the rate of humus decomposition
        
             
        
        
        
1 Nitrogen Fixing.
2 Decomposition and Ammonification.
3 Nitrification.
4 Denitrifying bacteria.
 
        
             
        
        
        
Most DNA is found in the cell nucleus
        
                    
             
        
        
        
Unlike a bar magnet<span>, however, </span>Earth's magnetic field<span> changes over time because it is generated by a geodynamo (in </span>Earth's<span> case, the motion of molten iron alloys in its outer core).</span>
        
                    
             
        
        
        
Answer is C A 20kg object