A spiral galaxy is being shown
        
                    
             
        
        
        
The main reason is that there is no atmosphere. This means that there is no weather and no weather means that there is no wind or rain. Wind and rain are main components of erosion and because there is no erosion, craters can stay preserved for a very long time.
Hope this helps!! 
        
             
        
        
        
DNA replication<span> is </span>semi-conservative<span> because each helix that is created contains one strand from the helix from which it was copied. </span>
        
             
        
        
        
Answer : stomach to the liver
        
                    
             
        
        
        
Answer:
40%
Explanation:
Remember that guanine always pairs with cytosine, and thymine always pairs with adenine. That means that any time there is a guanine, there is always a cytosine.
If there are 10% guanines, then there are 10% cytosines. That means the total of guanines and cytosines is 20%. 
The other 2 bases (thymine and adenine) have to make up the rest of the bases. That means they have to make up 100-20 = 80%.
Again, there will be equal amounts of thymine and adenine, so 80%/2 = 40%.