You are running an experiment on photosynthesis rates using the aquatic plant Elodea. Predict how the number of oxygen bubbles will change with different distance from the light source.

I would say A. Production of oxygen bubbles will not change based on distance of plants from the light source.

Explanation:

This is because distance from the light source doesn't really matter in terms of the rate of photosynthesis. The role of light in photosynthesis is simply to provide the electrons necessary to kick of photosystem I in the light-dependent reactions. Whether far or close, the electrons will be supplied (think about the Sun). :)

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.