Activation of muscle contraction could be a speedy event that's initiated by electrical activity within the surface membrane and transversal (T) tubules. This can be followed by unharness of metal<span> from the inner membrane system, the sarcoplasmic reticulum.
</span>Nervous stimulation causes a depolarization<span> of the muscle membrane (sarcolemma) </span>that<span> triggers </span>the discharge<span> of </span>calcium<span> ions from the sarcoplasmic reticulum.</span>
        
                    
             
        
        
        
I think format? or formula?
        
             
        
        
        
Answer: 
c) solar energy is renewable because it will be available as long as the sun continues to burn
To be specific, it's indistinguishable