Explanation for Question 21 From the Writing Section on the 2019 October Sat
Now question number 21 is asking us to find the main idea of the 2 paragraph and encapsulate it in a sentence. 3 So let's take a look at what this paragraph is telling us about, 4 right? It tells us about a research study that compare the blue light, 5 and we see that, um, blue light is L is effective at 6 elevating temperature and heart rate. And then it goes on to say that it 7 suppresses melatonin, um, 8 which helps you sleep at night by making you feel tired. 9 And so the reason that these going to be our best answer is because 10 it shows us that connection between everything that we just listed, 11 right? Having a high temperature, having your heart racing, 12 maybe not racing, but an elevated heart rate, 13 right, going faster. It prevents you from releasing the hormone that helps you sleep, 14 right. And then D kind of brings all of that together, 15 strings it all together to show us that a major conclusion here is that 16 blue light disrupts sleep. 17 So do you kind of combines everything together, 18 but we can also see why our other answer choices are wrong. 19 Um, now melatonin plays an important role for the sleep cycle. 20 This is true. It's connected to the sentence above, 21 but it has no connection to blue light to blue light, 22 which is a big part of this paragraph. Now B says, 23 since wavelengths occur outside the blue light range do not inhibit release of melatonin. 24 People do not have to give up electronic devices in the evening altogether. 25 Um, an...