Mass can be measured with a triple beam balance in units of a. grams b. newtons c. cubic centimeters d. millimeters

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.

the correct answer is:

a population changes in response to a change in the environment.