That's why I always recommend starting with a blog or website first. Create a content website on a very focused theme/niche. Build up traffic to that website through continuous, useful updates. Learn how to market the website, and as your following grows, then you'll have people to promote your social network to.
Human body. The human body is the entire structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head, neck, trunk (which includes the thorax and abdomen), arms and hands, legs and feet.
Oxygen therefore contributes a majority of a human body's mass, followed by carbon. 99% of the mass of the human body is made up of the six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus.