Why are fences put along some beaches ?
a is to increase water erozion
b iis to prevent wind erosion
c is to increase weathering
d is to prevent deposition

The answer is; B

Sometimes winds carry the sand of the beaches causing erosion. The fences act as breakers of this wind erosion. As wind tries to carry the sand, they encounter the fence and 'break'. Therefore, the sand is deposited along the fence forming a sand dune. These dunes also form protection from storm surges.

the answer would be   10%

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.