What is the main cause of poor air quality and acid rain? 1-Trees and greenhouse gasses
2-Water vapor and sulfuric acid
3-Deforestation and methane gas emission
4-Greenhouse gasses and smog

gold i'm pretty sure i might be wrong

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.