Which disease caused by a sporozoan results in over two million deaths a year?
a. african sleeping sickness
b. hiker's diarrhea
c. malaria
d. the flu

the correct answer: the index of refraction of the second medium is lower i tried this persons answer and it was wrong this person is lying

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.