A hummingbird drinks nectar from a flower and carries its pollen to other flowers. What is this an example of?

a.) defensive mutualism

b.) parasitism

c.) commensalism

d.) dispersive mutualism

D. dispersive mutualism

c

explanation:

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.