Why do the explanation notes use "some" notation in the diagramming? I think I follow but there's no clear explanation for the diagramming notation. I didn't diagram it like the notes or the way it's done in the video (which doesn't match the diagrams in the notes) but was able to arrive at B. Can there be some clarification on this?

@Kevin_Lin sure, but it strengthens Miranda's argument more which is why it seems like a trick. On many questions, missing that kind of subtlety means you get it wrong.

Had A, switched to C because the purpose didn't really seem to be to refute 'certain researchers' (no one is explicitly named; to me, 'certain' implies some specificity). It seemed to me that most of the passage is about evidence that counters the claims/evidence at the end of P1.

The explanation for why C is wrong seems off? The link goes to the sentence before the part that I would call evidence, and so doesn't address the claims/evidence that follow. If 'some researchers' can mean 'certain researchers' then I think it's reasonable to say that those statements count as evidence being refuted. More complete explanations in the ACs would be great.

@Tumptytumtoes Not sure why the explanation for D doesn't say it, but paragraph 2 also says, "Subsequent population variation in the extent and timing of dental reduction is broadly explicable by regional variation in the times when improvements in cooking technology were adopted." So changed and improvement are addressed

@Stas1973 Glad that worked, but FYI Sabina says "if the words are clearly defined and consistently used..."

Didn't choose B because this wasn't a 'stated' question. Asking whether or not the author would agree with something that they stated in the passage seemed like a trick. For an implied question, D seemed like the best (though not great) option. The author is arguing that a fiction/novel narrative style to tell an autobiographical story results in what I would say is a powerful outcome, implying that it is better or more effective for an autobiography to tell a powerful story. I didn't love it, but B is stated so... Do we assume that if it's stated that's the correct answer?

On what question types is okay to choose an AC that assumes what has happened in the past will continue to happen in the future? Is it just on a weaken question like this one? It seems like D could be pointed out as a flaw if it was in the stimulus. Not sure why I would assume, given the increasing frequency of El Niño, that past heavy-but-not-sustained rainfall patterns would continue.

meditations don't seem to be working still? browser issue?

I'm a little unclear on the explanation for A.

It reads: "If... even one of the coolest brown dwarfs used to be hot enough to destroy lithium, then it would be possible to find one of the coolest brown dwarfs that contained lithium."

Why isn't it, "...contained no lithium"?

The CBDs can't contain no lithium (because then they would be the 'any star' referred to in the stimulus), so that means they must contain lithium right?

@SasisaL28 You mean contrapositive for #3?

@TheBigFatPanda it usually implies "odd" or "peculiar" so that's what seemed to me like it wasn't the right answer, even though all the others also seemed wrong