Although no blueprints of the pyramids have been found, what evidence suggests humans, not aliens, built the pyramids?
remains of large work horses
an ancient rock quarry
advanced forms of technology
wheeled wooden carts

a

explanation:

easy

explanation:

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.

carbon atoms, hydrogen, oxygen, and nitrogen.