Why is this the answer?

The answer is air because this clever riddle describes something that is all around us, keeping us alive every second of the day. It is one of the most necessary things on our planet. Let us look at the clues one by one, just like a detective searching for important evidence to solve a mystery. The first part of the riddle says, "I cost no money to use, or conscious effort to take part of." Think about the most important job your body does all the time without you even having to remember to do it. That is breathing! Air is totally free for everyone on Earth. You do not have to buy it from a store or pay a bill to use it. Even better, you do not have to think "breathe in" and "breathe out" all day long. Your amazing body just does this job automatically, without any conscious effort on your part. Air is a constant gift that you get to use all the time. The next clue is a little bit tricky because it describes how air looks. It says, "And as far as you can see, there is nothing to me." When you look across your classroom or outside at the park, you cannot actually see the air. Air is a clear, invisible mixture of gases. You can sometimes see things move through the air, like dust, or feel the air move when it is windy, but the air itself is completely transparent. It truly looks like nothing is there, which is exactly what the riddle says. Even though it is invisible, air fills up every open space around us. Finally, the last clue is the most important one: "But without me, you are dead." This clue tells you how essential the answer is. Every living thing, from a tiny bug to a big whale, needs air to survive. Air contains the oxygen that our lungs take in and send to the rest of our bodies. Without that oxygen, our bodies could not work, and we would quickly die. You only have to hold your breath for a short time to feel how much you need air. This is why air is so incredibly important and why this riddle is so smart. It perfectly describes how air is free, invisible, and necessary for life, which is a perfect match for all the clues.