Answer:
<em><u>Weathering & Erosion </u></em>
Explanation:
Weathering & erosion of the Colorado River is the reason the Grand Canyon exists in the first place. (Or Paul Bunyan)
Is this supposed to be a multiple choice?
<span>These senses may be exhibited as early as around the 6th month. When shown two shapes, one of which was considered the "helper" and one a "hinderer," the infant showed a willingness to spend more time playing with the "helper" shape than the "hinderer."</span>
