Answer:
The correct answer is - loss of soil moisture east of mountain ranges.
Explanation:
Air or wind with moisture moves towards the top of the mountains where it precipitates and condenses before crossing the mountains and when this air crosses there is no moisture left in them to precipitate on another side.
The other side called rain shadow and is forced to become the area desert in the long run which is called the rainshadow effect. The major effect of the rainshadow effect is the formation of the deserts in a natural way.
 
        
             
        
        
        
The answer is ribosomes. Ribosomes produce proteins for the cell.
        
                    
             
        
        
        
The definition of vestigial organs are rudimentary structures in humans
that correspond to a functional structure or organ in an ancestor.
Basically the answer is redundant organs present in an organism, which
have been functional in the organism's ancestors.
        
                    
             
        
        
        
Definite article is used before a noun (person place or thing) to indicate that the identity of the noun is known to the reader. 
indefinite article is used before a noun that is general or when its identity is not known.