Answer:
squamous epithelium consists of a single layer of flat cells. It is found in lungs,heart and blood vessels.It allows the movement of materials across it.
stratified epithelium has many layer of flat cells.It is present in lining of oesophagus and mouth and also over the skin
 
        
                    
             
        
        
        
I think the answer would be 420hg=4,200,000cg
        
             
        
        
        
Answer:
D
Explanation:
Control group in an experiment does not receive any treatments. It is used as a benchmark to ensure that there is statistical difference in data between the variables of the control and those with treatments. It also ensures that there are no other overlooked factors that have an influence on the experiment that needed to be considered. Having a control group reduces the chances of erroneous conclusions.  
 
        
             
        
        
        
Just guess, sorry im lazy..or just wait for better help XD