The brain, bones, and muscles work together to help people move. What other organs work together to support movement in the body? A
liver and lungs
B
liver and bladder
C
heart and bladder
D
heart and lungs

the answer to your question is:

c. complementary base-pairing

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.