What is an organism that relies on other organisms for its food and energy supply; also called a heterotroph?

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.

acceleration= v2-v1/t so 8m/s-3m/s / 3s =to 8/3 or

2.67 m/s^2

hope i

-lavira: )