<span>mitochondria ribosomes endoplasmic reticulum</span>
The first one, cause their trying to make it a positive way to reinforce. Which just means their trying to fix something again
Counter current involves blood in the capillaries flowing in the opposite direction to the flow of water flowing over them. Gases diffuse faster from one area to another when the concentration difference between the two areas is at its greatest, as compared to when the concentration difference is low.
D. Muscus and cilia trap pathogens
have a good day!
