The Right Answers

Blank 2: It's easier to start with Blank 2 here. We can use Math Strategy from "despite" onwards. On the RHS of the comma, it says that he is never unclear, so the LHS should be contrasting to that, specifically something that suggests he might have appearedunclear. Blank 2 describes his "orthographic" or language rules, so in order to be unclear, it should be something like "bad".

The best match for this blank is disregard for , which suggests he rarely followed language rules, indicating a reason why he might be considered unclear.

Blank 1: Now that we filled in Blank 2, we can solve Blank 1 using the Previously Referenced strategy. Later on in the sentence, when filling Blank 2, we deduced that his "orthographic rules" were bad. Just before that, we can spot a "this", which means that the idea is the same as one previously referenced in the sentence, specifically the nature of his spelling. So, similarly Blank 1 should also be something like "bad"..

The best match for this blank is defiant, which suggests that he is not following correct spelling rules.

The Wrong Answers

Blank 1

indefatigable: This choice has no evidence. There's nothing suggesting he was persistent in the way he spelled things.
fastidious: This choice contradicts the logic. The blank should convey that he was a bad speller, not one who took great care with his spellings.

Blank 2

partiality toward: This choice contradicts the logic. If he had partiality toward the rules, there's no reason to contrast this by saying he is never unclear.
unpretentiousness about: This choice has no evidence. We don't know anything about how "pretentious" Clark was, from this sentence.