The answer is C. nitrogen.
Plants are main producers in ecosystems so, primary productivity of ecosystems depends on them. Carbon is necessary for plants, but it is widely present in plants. On the other hand, calcium and sodium are not as essential. However, nitrogen is important for plants because it is necessary to make proteins. Proteins take part in many different processes such as photosynthesis (this is actually primary productivity). But, nitrogen is not available to plants, they cannot absorb it simply from the air but rely on some symbiotic bacteria which are able to.
Answer:
Explanation:
Function and structure are related, because of a certain structure a living thing make contain makes the object function the way it does. ... The relationship of a structure and function is the structuring levels from molecules to organism ensure successful functioning in all living organism and living system.
My theory is that . Mybe it changed because the flavor composition of the cracker changed or it dissolved in the saliva.
THEORY. :'3