A Paramecium has an internal sucrose concentration of 0.040 M, a glucose concentration of 0.035 M, and a fructose concentration of 0.0050 M. The Paramecium is placed in an aqueous solution that has solute concentrations of 0.025 M for sucrose, glucose, and fructose. Which solutes will diffuse out of the Paramecium? a. Glucose and fructose
b. Sucrose and fructose
c. Sucrose and glucose
d. Sucrose, glucose, and fructose

c. Sucrose and glucose

Explanation:

The paramecium is a large, single-celled microbes, surrounded by a plasma membrane. Simple diffusion occurs in cells across plasma membranes, as a form of passive transport. In diffusion, solutes move from regions of high concentration to regions of low concentration across the plasma membrane.

Here, the internal environment has higher concentrations of sucrose and glucose, but lower concentrations of fructose, thus the solutes will move along their concentration gradient, to where the concentrations are lower. In order for the fructose molecules to move out of the cell, the molecules have to move against their concentration gradient - a process requiring energy known as active transport.  

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.