Does anybody know the answer to these?

the answer is b.) hydrogen bonds between bases.

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.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

its probably to later but whats the question