Answer:
A prepositional phrase is a modifying phrase which includes a preposition (in this case, "over") and the object of the preposition (in this case, "the mantelpiece.")
Borges's story The Garden of Forking Paths can be considered to be a three dimensional chess game for a variety of reasons. First, like a game of chess, a nearly infinite number of possible outcomes are proposed through the story (just as how a chess game can allow for a variety of different outcomes). Also, chess is a game of choice, just as the Garden of Forking Paths - both the story itself and the novel of the same titles mentioned in the story - allows for the reader to, in essence, choose their own design and strategy. Furthermore, the lead character\protagonist in the story is manipulating events throughout the story to, in essence, score a "checkmate."
The sentence <em>Sickly people cost the company a whole boatload of dough </em>is not acceptable because the sentence contains a loaded word as well as slang.
You cannot use slang words such as <em>boatload </em>or <em>dough </em>in formal English.
Sometimes this is true but not entirely so I would say false
