i think it is 3a because when they are all together they are in like a clump so
 
        
             
        
        
        
Answer:
They tunnel through the soil, which allows air to enter.
Explanation:
Earthworms are considered to be agriculturally friendly living organisms that hold immense importance in improving the growth and productivity of plants.
They live in the soil and feed on the debris of plants such as manure, grasses, roots and dead leaves. They extensively channel and tunnel through soils while moving that causes loosening of the soil resulting in more aeration of the soil. The more the soil aeration is, the better soil drainage is.
Studies have shown that soil containing earthworms have ten times better drainage than soils that donot have earthworms. Therefore, C is the best option.
Hope it help!
 
        
             
        
        
        
A chemical reaction happens
        
             
        
        
        
Histology is the study of blood, which is a group of similar cells that have a common function.
<h3>What is blood?</h3>
Blood is a connective tissue that contains cells known as red blood cells, while blood cells, and platelets, and is responsible for transport of different substances, is referred to as blood.
The study of blood is histology.
Thus, the answer is histology.
For more details regarding histology, visit:
brainly.com/question/10865552
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