Which phase of the writing process involves checking the content to see if the essay is sufficiently detailed and adequately supports the thesis statement?
drafting phase
revising phase
prewriting phase
editing phase

I would say the editing phase, as I have done a lot of writing and multiple people around me refer it as that, but the revising stage also covers editing, which doesn't make much sense. I guess that it depends on what your class taught you. Sorry if this doesn't help you, but my best answer would be the editing, since it covers going back through a paper to check for errors. Do you know what the exact definition of "editing" and "revising" is and could you get back to me with that?

Not sure if there was any sort of picture or something to go along with this but my guess is the book went into deep depth and was very informative.

Her taking a guess here..