Mrs. Lewis set up a lab for her biology students using a culture of the small crustacean Daphnia, obtained from a pond that was 20°C. The students are to investigate the effect temperature has on Daphnia. The students will observe the crustacean’s heartbeat under the microscope, at different temperatures, and count the number of heartbeats per sec. What is the independent variable in this experiment? 5 points

mr lewis planted 121x13 then esmiate the answer in 2 diff ways

Explanation:

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.

looks like the answer is     c     to me!