On the SAT verbal section, what is a good strategy for approaching the "fill-in-the-blank" questions, if they have two or three different blanks?
Sometimes, these questions will be relatively straightforward. At other times, however, you'll be confronted with a first blank that has two possible answers that both make sense - except they're antonyms, so picking either will vastly change the meaning of the sentence. To decide between cases like these, it is conceivable that you'll have to move on and go to the next blank, which may have only one reasonable answer that fits with the first blank and will then help you 'work backwards' to solve the answer. Here's an example: "In a ______ (jubilant, sullen) mood, the student proceeded to rapidly ______ (excoriate, forgive) his friend for accidentally spilling pasta sauce on his shirt". Here, the first blank has no immediately obvious answer; the student could be in either a positive or negative mood, and both could be plausible. Therefore, we have to move on to the next blank, and look at it in tandem with the first to see which fit together to make a reasonable pair. Would a sullen (ie. sad) individual readily excoriate (yell, be furious) with someone else? While both words indicate a negative demeanor, they don't fit nearly as well together as the other option: a jubilant (happy) student extending forgiveness on account of his good mood.
What are some tips on doing well on the essay sections of the GRE?
As someone who got a perfect score on the GRE writing section, here's a tip to keep in mind: you should be ready to approach the two essay sections each in a different way. To prepare for the "Analyze an Issue" section, do some practice with prompts (all of them are available on the ETS website) to hone your critical thinking skills. Here, it's crucial that you support any stance you take with *specific examples*; especially from the real world! Therefore, it'd be a good idea to have a few go-to historical examples that you can pull out to support your argument, so do a bit of reading on wikipedia! Take a look at certain figures who stood behind momentous historical changes, such as Nelson Mandela, Gorbachev/Reagan, and so on. In this essay, you want to make sure you work in specific examples to prove your point. The "Analyze an Argument" section is arguably easier for two reasons: you already know which side you're supposed to take (spoiler: you have to counter the argument), and because you don't have to use any specific, real-world examples. In other words, this is the section where you can let your imagination fly in trying to come up with all kinds of scenarios and reasons for which the argument could be faulty. Let's say one piece of the argument is, "a recent study found that more individuals were willing to eat at a restaurant for dinner rather than for lunch, thus the restaurant in question should reduce their lunch hours to make more room for longer dinner hours". Think of whatever potential, theoretical issues you perceive: no data on how large the gap in 'willingness' recorded in the survey was, no data on whether the survey was representative, no data on whether more customers would come if the dinner hours were extended, and no data on what hours individuals would most want to go out to eat. Let's say about 60 people went to eat lunch at this restaurant on a given day, and 80 to dinner. Even then, if the lunch hours are significantly shorter than the dinner hours (say, 3 hours for lunch and 8 hours for dinner), that would mean an average of 20 customers arrive per hour for lunch and only 10 for dinner - and thus reducing the lunch hours could actually *decrease* the number of customers! Thus, unlike the "Issue" essay, this one is a lot more loose - no need for any specific examples, so let your imagination come up with as many good, possible faults with the argument as you can!
In organic chemistry, how can I tell whether a reagent that is both a strong nucleophile and a strong base (like OH-) undergoes nucleophilic attack or elimination?
In this case, we're dealing entirely with strong nucleophiles and bases. Generally, the rule is that methyl and primary carbons undergo nucleophilic attack (except if the nucleophile is extremely bulky, like a tert-butyl group) and tertiary carbons undergo elimination. What about secondary carbons, which can easily undergo both? The key to the answer is the number *13*. If the pKa (ie. the acidity) of the neutral/acidic form of the nucleophile (ex: H2O if your nucleophile is OH-) is below 13, it will add as a nucleophile; if it is above 13, it will eliminate. Hence, CH3O- (pKa of CH3OH = 17) will eliminate at secondary carbons, while CN- (pKa of HCN = 9.2) will add.