I think verterbrates have a back bone others do not. I only THINK so.
 
        
                    
             
        
        
        
Cells of various types have different functions because cell structure and function are closely related. It is apparent that a cell that is very thin is not well suited for a protective function.
        
             
        
        
        
Answer:
Option C,  Intrapleural pressure is less than intrapulmonary pressure
Explanation:
During inspiration, the air enters the lungs due to lower pressure in the intrapulmonary or intra-alveolar  than the atmospheric pressure. During quite respiration, the intrapulmonary pressure reduces to a pressure that is 3 mm Hg lower than that of atmospheric pressure. During quiet expiration, the intrapulmonary pressure rises up to a pressure that is 3 mm Hg higher than that of atmospheric pressure. This leads to lack of air in the intrapleural space thereby producing intrapleural pressure which is lesser than that of intrapulmonary pressure.  
This difference in pressure (i.e higher pressure with in the lungs than the atmosphere)  causes lungs to remain attached to the chest wall and hence looks inflated.  
Hence, option C is correct
 
        
             
        
        
        
Answer:
The answer is- A). Because it takes tremendous effort to break free from the laws of gravity to exit the Earth's atmosphere.
Explanation: 
I really don't have an explanation. Except that I love science and I actually pay attention in my classes.
  
        
                    
             
        
        
        
Answer:
because it is also created from the father not only one of them