What are capillaries and what do they do

Capillaries are very thin blood vessels that were first discovered in frog lungs in 1661. They bring nutrients and oxygen to tissues and remove waste products.

the solar system used to have much dust particles option no d

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.