How to improve my SAT Critical Reading score?

I have taken the SAT twice and recently I got 570 reading, 740 math, and 780 writing. I completed the Collegeboard SAT blue book and have taken probably 15 practice tests total for the SAT. I don't how to improve reading no matter how hard I try. I really need to improve to a score around 700 for reading. I'm going to be senior, any advise for what I should do before the end of summer? Please don't just say read and read because even though it helps, I'm running out of time. (By the way, I think my problem is that I can't concentrate completely when reading, what do I do about that?) Thanks so much for the help.