What are the three things that blood is responsible for transporting through the body.
Nerve impulses
wastes such as CO2
French fries
oxygen
nutrients
DNA

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

because they are eaten by the frog and the frog getseaten by the snake and the snake by the eagle