Epithelial tissue
It is also widespread thought the body and covers organs.
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.
Skeletal muscle! (or striated muscle).
For me I love gaming but at the same time I have homework. So it is hard for me and I'm going through it right now but improving me. You must first think which one is important. Like is gaming important over homework or homework importance over gaming? You might choose the second one, why? It is really simple, you must first think about it. Homework that is due the net day must be done and today is the only day to do it. Gaming, you can play after homework since it is not due the next day, it is not gonna effect your life and future. And to understand what you are reading is to metaphor. To imagine the scene out on your mind. Make gist every paragraph you read and as questions.
Sunflowers due to the fact that the top of it is entirely of nectar
