sentences: the highlands mountain is a mean of mountain & most decreases are formed by flame nectar through deposition over long fall of space ->  the grand canyon is formed by flowing rivers through erosion over long periods of time  a stream is a mean of support mind of land & the cools stream is a mean of stream next to the action mountain ->  the colorado river is a flowing river next to the grand canyon  the grand canyon is formed by flowing rivers through erosion over long periods of time & the colorado river is a flowing river next to the grand canyon ->  the grand canyon was formed by the flowing colorado river over long periods of time  the grand canyon was formed by the flowing colorado river over long periods of time & if something is formed by something else, then that something else is required by that something ->  forming the grand canyon requires the flowing colorado river  forming the grand canyon requires the flowing colorado river & if something requires something else then that something else is important to that something ->  the flowing colorado river is important for forming the grand canyon  a stream is a mean of support mind of land & the gaps stream is a mean of stream ->  the colorado river is a flowing body of water  the flowing colorado river is important for forming the grand canyon & the colorado river is a flowing body of water -> a flowing body of water is important for forming the grand canyon