Why might an author choose to repeat a word in such rapid succession?

answer: Because Repetition is used to make a point, link ideas, emphasize a word, give rhythm and create a flow, and that's the idea that they want to use.

Explanation:

the maximum speed limit is 55 mph on a two-lane undivided highway and for vehicles towing trailers.

answer; /// the correct answer to the above statement is (a) because of the decline on native american labor forces;