Boxing career of Muhammad Ali. This is the latest accepted revision, reviewed on 29 April 2020. Cassius Marcellus Clay Jr. so therefore he chose boxing
Pile is the subject which is singular so the answer is A (is)
<span>A proper adjective is a proper noun used as an adjective, like "That's a Canon camera." Canon could be considered a proper adjective. They're used often but not the most frequently.
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