SC-
Manhattan Gmat always over estimates your verbal score. I was scoring low to mid 40's and only recieved a 35 on the test. That being said, my scores shot up once I learned all the Sentence correction rules. The manhattan gmat SC book is the best book out there- no one has ever disagreed with this. If I were you, I would go through the book slowly taking notes. Maybe spend a good week disecting the book. Then you could read it over faster and review. Once you learn rules such as not using "like" where you should use "such as", you will be able to get rid of at least 2-3 choices in a matter of seconds. I learned the rules well and got maybe 3 wrong when doing the first 50 in the og. The harder ones come later when the gmat knows that you memorized the rules... now they want to know if you can notice the flow, meaning, and point the sentence is trying to make- that is much is harder. Its all practice. If you do 200 SC slowly, learning why each answer choice is wrong, you'll pick it up very quickly.
RC- What I do for this is for each answer try and see why each other choice has to be wrong. The gmat writers cannot make an answer that can be right or wrong depending on the reader. There is a reason, it maybe a single word, why each answer choice is 100 percent false. You have to try and find the word or meaning.
CR- Came more naturally to me. Not sure what to do for this.
