Answer:
1) semicolon
2) comma
3) semicolon
Explanation:
semicolons are used to separate two independent clauses. Independent clauses are phrases that make sense on their own. The comma is needed in #2 because the phrases don't make sense on their own. In that case, a semicolon wouldn't work there. 
 
        
             
        
        
        
Workers lives were devalued over the protection of goods.
Workers often lived in horrible urban conditions with few legal protections, long work hours, and in humane factory conditions.
 
        
                    
             
        
        
        
Pro shows the good side of things cons show the bad side of things