Biological catalysts i think but not sure
Sternal angle marks the joint between the sternum and the 2nd rib.
Option E.
<h3><u>Explanation:</u></h3>
Sternum is the breast bone which is a dorsi ventrally flattened bone present in thorax of human. It gives the support for the ribs where the ribs join. A sternum has three parts - Manubrium sterni, body of sternum and the xyphoid process.
The sternum has attachments of a total of 10 ribs and clavicle. The clavicle and the first rib joins in the Manubrium sterni, and the 3rd to 10th rib joins in the body of sternum. The 2nd rib joins in a facet which is partly in Manubrium sterni and partly in body of sternum. This place id also called the sternal angle. So the sternal angle marks the joint of 2nd rib to sternum.
Rabbits,elk, and so forth rabbits have grass and roots
The answer is D) desertification and deforestation
To know the answer you can rule out the non-possibilities. A is not correct because farmers use them all the time. B is not correct because water and pesticides can flow downstream and carry and deposit sediment. C is not correct because farmers can flood their own farms. When they plant things and a food comes, all of those plants will die or their roots will detach which lowers the food that can be sold. D is correct because farmers don't farm in the desert or the forest, so it would not be an impact of farming.