“in a 2009 study, presented by the national academy of science, 97% of climate scientists agree that human activity is causing global warming." which of the following statements is best supported by this study?

answer:   97% of climate scientists

explanation:

this is because that was one of the precentages they came up with.

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.

layer 3 is younger than layer 6.