-10grade/week
Explanation:
Given parameters: 
Initial grade = 95grade
Final grade = 65grade
Time = 3weeks
Unknown parameter: 
Rate of change of grade = ? 
Solution: 
Rate is defined as the change of a quantity with time. 
  Rate of change of grade  = 
Rate of change of grade  =  =
 = 
Rate of change of grade = -10grade/week
The rate of change of the student's grade is -10grade/week. It implies that the grade of the student reduces by 10unit per week. 
 
        
             
        
        
        
The answer is c because they are not identical to parents but have some things in common ( resemble)
        
                    
             
        
        
        
I don't know what your question is but if you're wondering what is called when water changes from a gas to a liquid phase the answer would be Condensation
 
        
                    
             
        
        
        
Hair and nails are part<span> of the integumentary </span>system<span>.</span>
        
                    
             
        
        
        
The red blood corpuscles have a pigment called hemoglobin that binds to the oxygen and carries it to the whole body in both the conditions, when the body is at rest or when the body is exercising. The oxygenated blood from the heart is carried to the various parts of the body and the de-oxygenated blood from various parts of the body is carried to the lungs where the exchange of gases takes place.