Oxygen is taken from the water by

Explanation:

Humans use their lungs to inhale oxygen from the air. But worms, fish, crabs and other underwater animals use gills to get oxygen from the water. As water moves across an animal's gills, oxygen is removed and passed into the blood. Gills work better when there is more oxygen in the surrounding water.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

ι вєℓινє тнє αиѕωєя тσ уσυя qυєѕтισи ιѕ в. ℓуѕσѕσмє

ι нσρє тнαт ι ¢συℓ∂ нєℓρ уσυ.