Sometimes, the dark spots on the marshmallow can fall off  of the marshmallow. This means that, the system does not need to include  the pieces that fell when determining the  mass before and after.
 
        
             
        
        
        
It is further evidence for the theory of plate tectonics. 
Hope this helps! :)
        
                    
             
        
        
        
Answer:
B.
Explanation:
Seems most reasonable to me but I could be wrong
 
        
             
        
        
        
Answer:
The intracellular is where enzymes need to perform optimally or near optimum.
Explanation:
The Km is the concentration of molecules where an enzyme performs at half of its maximum velocity (Vmax). Therefore, when molecules are near Km the enzyme is able to hydrolyze molecules nearer its Vmax.