An example would be the great mistakes he's made
The given statement is an example of a phrase, specifically, a participial phrase. The element that is necessary to complete the sentence is an independent clause. A participial phrase consists of words with the -ing or -en form plus its modifiers. This kind of phrase always functions as an adjective. The phrase "Beginning in the fall of 1957" is describing a certain noun, which is found in the independent clause.
Answer:
the river eroding the canyon, revealing layers of history that represent billions of earth years. ... Peering into the Canyon from the rim is like living life on the surface.
Explanation:
Not exactly sure what the question is :)
The main theme is the fragility of sanity, guilt versus innocence, and the unrelenting passage of time. The fragility of sanity: the narrator's attempt to prove his sanity, his erratic mannerisms while he explains his meticulous plans for killing the old man only prove his madness.