Answer:
Are caused by bacteria viruses or parasites
Explanation:
not all cause visible symptoms 
it would not be a sexual transmitted infection if not caused by sexual contact
STIs can be contracted by men and women 
 
        
                    
             
        
        
        
 Students hypothesized that adding lactose to a sixth test tube would produce the greatest amount of carbon dioxide.
This is because lactose is a sugar molecule that is the food source for the yeast.
Fermentation is a metabolic pathway that occurs anaerobically, meaning in the absence of oxygen (O2). It includes the process of glycolysis with some extra reactions which make alcohol.