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https://gmatclub.com/forum/poaching-in-africa-has-been-the-greatest-threat-to-245489.html - In this question, the usage of "have" in correct choice E is wrong. Have is used for an event that started in the past and still continuing in present.
Remember, it's about the best of the five answer choices. If you chose D or any other answer choice, you missed a howler.
Besides, the present perfect continuous is "acceptable" (though yes, simple past would be the obvious choice) because such measures (and their practical implementation) are likely to be still on as the problem still persists.
Quote:
https://gmatclub.com/forum/martyrdom-a-word-with-its-root-in-the-greek-martur-which-means-witne-246393.html - absence of parallelism marker in the correct choice. IMO, Choice A should be the best amongst all.
Again, it is about the best of the 5 answer choices; yes, D is a bit awkward with the comma splice at the end but options such as A commit a fundamental error of changing the meaning by making things not parallel in meaning (2 extremely positive things followed by something negative), parallel. The first 1-minute in the video explanation will help-
https://www.youtube.com/watch?v=xDuriPJ7Br8These are high difficulty questions with some serious traps in correct-sounding choices and subtle compromises (not the "completely incorrect" connotation) in the correct answer choice- as one will sometimes see on the GMAT. Had these been official questions, the "experts", with due respect, would see deeper and appreciate the nuances while remembering the "best of the 5 and not 'perfect' answer choice" rule.
Regarding finding our explanations inadequate, I am not sure whether you used the video explanations together with the text explanations.
Quote:
It would actually serve as a relief if you justify the correct options. I'm be off this dilemma of which third party mocks to purchase & I'll purchase
experts global in a go :D
This isn't about a "purchase". Avoid.
Suggestion, as a senior:Looking at your doubts, my overall observation is that you are in that phase of sentence correction prep where the emphasis is on "rules" (are you an Indian engineer?

) and the maturity to understand the nuanced difference in "meaning" is yet to fully come; nothing strange- we all go through that phase. Just hang in there with a student-like attitude and you shall sail through. All the best!
Good luck with your prep, Vishnu.