Answer
Nutrient loss and soil erosion
Explanation:
Phylum - <span>taxonomic category containing classes with similar characteristics . . . . </span>
I believe the answer is B
The generation of an action potential in a neuron requires the presence of<span> voltage-gated channels, which are </span><span> a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the <span>channel.</span></span>
The Rocky Mountains formed 80 million to 55 million years ago during the Laramide orogeny, in which a number of plates began sliding underneath the North American plate. ... Since then, further tectonic activity and erosion by glaciers have sculpted the Rockies into dramatic peaks and valleys.
Most of the present physiographic regions of the Great Plains are a result of erosion in the last five million years. Widespread uplift to the west and in the Black Hills caused rivers draining these highlands to erode the landscape once again and the Great Plains were carved up.
