Answer:
C. But see the answer under C. Apparently C is the accepted answer.
Explanation:
A. Not A.I don't think that's a problem for gulls especially on beaches.
B. Not B.  Their feather do not look like they need much help in keeping their feathers attached when in flight.
C. This is not really the answer, but it is the best answer of these 4. The actual answer is that the bones are porous for better air intake which provides more oxygen and hence they are better able to fly.
D. Not D. Food has nothing to do with the problem. Birds get an adequate amount of food without their wings being porous. See the answer for C.
 
        
                    
             
        
        
        
Stem cells begin to transfor into different types of cells in the human body in a process known as cell differentiation.
Cellular differentiation occurs throughout the cell development of a multi-cellular organism. It occurs when the cell changes from a simply zygote into a complex system of tissues and cell types. 
Stems cells are cells which have the potential to develop into many different cell types in the body during early life and growth. Stem cells serve as internal repair system in many tissues. When stem cells divide while undergoing cell differentiation, it can either retain being a stem cell or become another type of cell like muscle cell, brain cell, or red blood cell.
 Read more on Brainly - 
brainly.com/sf/question/817155
 
        
        
        
Answer:
Earthquakes
Explanation:
This would happen because we have devices such as seismographs to record the motion of the ground during an earthquake. Without that, we wouldn't know how big the earthquake is and how to prepare for survival. 
 
        
                    
             
        
        
        
The answer is B- Embryological Development.
        
             
        
        
        
The most abundant element in the atmosphere can also be is nitrogen since nitrogen gas accounts for about 78% of the atmospheric gases. Beans and whey protein are, of course, high in protein, and a fundamental component of proteins at the molecular level is a nitrogen-containing group called an amine group.