Air enters and exits the lungs through the ___. aveoli
bronchi
pulmonary vein
trachea

It has to be b i hope this

Change in speed or direction : )

Your question is not clear but if you can explain yourself i would be glad to .  just trying to : ))

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.