Explanation:
do number one like that and do number two different
 that is systems with essentially only two energy levels are
important kind of systems, as at low enough temperatures, only the two
lowest energy levels will be involved. 
 
        
             
        
        
        
Viruses are non-living when they are suspended without a host body. As soon as they enter a host body, they become living. This nature makes it hard to classify viruses as non-living or living. Thus, antibiotics don't work on viruses.
<em>Hope</em><em> </em><em>this</em><em> </em><em>helps</em><em> </em><em>:</em><em>)</em>
 
        
                    
             
        
        
        
Permeability is the feature of a membrane
        
                    
             
        
        
        
Answer:
<em>It is the outermost covering of a cell that separates the contents of the cell from its external environment. </em>
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<em>It only allows the entry and exit of some materials. It also prevents the movement of some. Therefore, it is also called a selectively permeable membrane.</em>
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<em>Some substances like carbon dioxide and oxygen can move across the cell membrane due to the process known as diffusion.</em>
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<em>Water also obeys the laws of diffusion. The movement of water molecules through a selectively permeable membrane is called osmosis.</em>
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<em>Pls mark as brainliest.</em>