A metamorphic rock is a type of rock which has been changed by extreme heat and pressure.  so must be option D
        
             
        
        
        
The fertilized egg begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive theegg. ... At the end of this transition period, the embryo becomes a mass of very organized cells, called a blastocyst.
        
             
        
        
        
 movement of people from one permanent home to another. This movement changes the population of a place. International migration is the movement from one country to another. ... People who move into another country are called immigrants . 
 
        
                    
             
        
        
        
Answer:
The polar bear is an animal which is prevalent in the arctic region of the world which is characterized by very cold icy climate.
They adapt to these climatic conditions by maintaining a body temperature of 37°C through its thick fur and tough skin. It also has an insulating fat layer (adipose tissues) which is very thick.
This insulation helps in keeping the animal very warm in extreme temperatures.
 
        
                    
             
        
        
        
Answer:I think its B. but im not sure
Explanation: