scoring 700 but getting initial questions wrong

It's normal to get quite a few questions wrong, even at the beginning. You can't be at all sure that those initial questions are easy. Do they seem easy when you look back at them? Can you see what led you to miss them?

It's hard to improve on a Q49, but your verbal has plenty of room for growth. What aspects of the verbal section do you find the most difficult?

For CR/RC, the biggest thing you can do is to get better at predicting the answer up front. Don't dive into the answer choices until you have a clear sense of what you're looking for. ("Okay, I want to undermine the economist's prediction. What is that prediction? What support does the economist provide? Where is there a hole in the argument, and what kind of new information would expose that hole?")

SC relies a great deal on rules and a great deal on specific phrases and structures in written English. It's hard to cram in all the rules in a short time, and the phrases/structures can be the work of a lifetime. So over 3 weeks, it helps to find a few good focus points. For me, the most natural ones would be sentence structure and meaning. To focus on sentence structure, look at the simplified core of the sentence minus all the adjectives, modifiers, and descriptive phrases. What is the subject and what is the verb for that subject? Is that subject acting on something else?

Example: After adopting a healthier diet, Tom has found that the intense pain from his numerous chronic ailments have diminished substantially and that he falls blissfully asleep almost immediately upon climbing into bed.

After adopting a healthier diet, Tom has found that the intense pain from his numerous chronic ailments have diminished substantially and that he falls blissfully asleep almost immediately upon climbing into bed.

The parts not in bold are non-essential modifying portions of the sentence. While some of them contribute quite a bit of meaning (the sentence loses a great deal without that initial modifier about diet), they don't directly impact the structure of the core, which now reads as follows:

Tom has found that the pain have diminished and that he falls asleep.

Clearly, this is missing quite a bit of content, but in this form, it's easier to spot the subject-verb error: our sentence should read "the pain has diminished." Once we've narrowed our choices down to those that fix this error, we can step back and look at other issues such as modifiers and meaning.

It's easy to get stuck just looking at grammar, but it can really help to think about what the sentence seems to be trying to say in then compare that to what it's actually saying. When you look at SC that way, you can find many choices that work grammatically but just don't make sense logically. That's something you can get in the habit of looking at over the next few weeks, and it can make a real difference on the test!

I hope this helps.