Gather ingredients.
You gotta have it before you make it.
        
                    
             
        
        
        
Answer:
They need to see whether the chemical has been tampered with or not.  If the cap has been tampered with then it could mean somebody opened the product and possibly changed something in chemical.  Doing this can help prevent from something dangerous happen.  
Explanation:
 
        
             
        
        
        
Answer:
Assembly
This is a good word to replace Array. It means gathering. If you want to look for more words to replace Array, look at a Theasurus.