It’s Merriam-Webster’s word of the day today, so here is context clues worksheet on the noun crux. The crux of this to me is that it seems like a word–and a concept represented by the word–that graduating high school seniors ought to have in their linguistic toolboxes.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.