Saline solutions have the same or close to the same amount of salt as our blood does, so we get the amount of salt needed for our bodies. During blood loss, you lose the salt you need, so they're basically adding it back in with the saline solution, making your electrolyte balance go back to normal level. It also gives us the right amount of water to keep us hydrated.
Its dead plants and animals
Although the diagram is not provided, I have encountered it before. The region labelled "B" is a ring with two small particles on it. This ring is the electron cloud and is where the electrons move. Therefore, it is negatively charged.
