Solution caves are formed<span> in carbonate and sulfate rocks such as limestone, dolomite, marble, and gypsum by the </span>action of<span> slowly moving ground water that dissolves the rock to </span>form<span> tunnels.</span>
Biogechemical cycles depend mostly on bacteria and fungi for decomposition and the recycling of elements.
The sagebrush eats insects. When the insects land o the inside of the of the plant. the plant closes its mouth trapping the insects inside.
I believe the answer is D.
The independent variable should be the plants you used.