The expression or comment "Brain Freeze" means that the roof of your mouth is getting so cold that its affecting some of the nerves in your brain making it feel like a brain freeze.
        
                    
             
        
        
        
Answer:
The correct answer is b. Neutrophils
Explanation:
Neutrophils are the cells that first reach to the infection side and kills the bacteria. Neutrophils comprises most part of WBCs approximately 50-70% of total WBCs. Neutrophils kills the foreign bacteria by engulfing them and this process is called phagocytosis. 
The engulfed bacteria is called phagosome and phagosome then fuse with lysosome making phagolysosome. Now fused lysosome secrete lytic enzymes like proteases, lipases and glycosidases which kills the engulfed bacteria by digesting them. 
So neutrophils will be the first cells migrates to prevent bacterial infection in the hand of 20 year old boy who shoots his hand with nail gun.
 
        
             
        
        
        
Answer:
I think it is adding catechol oxidase
Explanation:
This is because more enzymes are able to take in more substrates, or reactants more quickly, therefore increasing the speed of the reaction.
Hope this helps!
 
        
                    
             
        
        
        
Answer:
When the heat energy releases and formation of iron oxide.
Explanation:
When the heat energy releases and formation of iron oxide are the indications that chemical reaction takes place. during the steel wool demonstration. During the steel wool demonstration, heat energy released when the iron combine with oxygen forming solid iron oxide. So we can conclude that release of heat energy and formation of iron oxide tells us that the chemical reaction takes place.