Outflow is the answer assuming that the underlined word is influx.
a figure of speech involving the comparison of one thing with another thing of a different kind, used to make a description more emphatic or vivid.
since a simile is where you compare 2 things i imagine the similie would be somwhere were he is talking about the maple tree. "before your could say jack robbison they have gone and grown alot bigger than you ever thought they could"
i had some trouble looking for it and thats all that makes sense for the similie i belive.
Answer:
the author uses caused and effect to explain why the appearance of policans changes
