Which revision would best the author support the thesis more effectively?

Which verb from is used to indicate the perfect progressive tense

Why do you think frank tashlin titled this story  the bear that wasn’t? why didn’t the factory officials recognize the bear for what he was? why did it become harder and harder for the bear to maintain his identity as he moved through the bureaucracy of the factory?

Buck did not cry out. he did not check himself, but drove in upon spitz, shoulder to shoulder, so hard that he missed the throat. they rolled over and over in the powdery snow. spitz gained his feet almost as though he had not been overthrown, slashing buck down the shoulder and leaping clear. twice his teeth clipped together, like the steel jaws of a trap, as he backed away for better footing, with lean and lifting lips that writhed and snarled. read this passage. explain what the conflict shows about buck and spitz.