The answer is B.
Water in the form of vapor enter the atmosphere. The vapor accumulates in the atmosphere to form clouds. Once the clouds are heavy enough, the water in the form of droplets fall towards land or as rain. It could also be in the form of other precipitation such as snow or hail. As the sun hits the waters in the land, it causes the water to evaporate and the cycle continues.
        
             
        
        
        
Answer:
 the procedure aims to replace the stem cells in the bone marrow the source of new red blood cells with healthy stem cells from a matching donor
 
        
             
        
        
        
The investigators could distinguish human hair from animal hair by the patter of pigmentation and by the medullary index.
The pigmentation in human hairs is denser toward the cuticle, whereas in animal hair is denser toward the medulla. Human hairs are usually one colour throughout the whole length, while animal hairs may change colour suddenly.
The medulla in humans is thinner than in animals: the medullary index for human hairs is 0.33 or less; the medullary index for animal hairs is 0.5 or more.
        
             
        
        
        
The population of Green-feathered birds decreases due to prefer other colour of male birds.
<h3>Why the population of Green-feathered birds decreases?</h3>
Green-feathered birds are becoming less and less common because of the female bird that choses the blue and red colour male for mating instead of green so that's why the population of Green-feathered birds decreases.
Learn more about mechanism here: brainly.com/question/1320373