It is not true. You can improve and it won't take years. We have worked with students where English is a 2nd language or even a third and they managed to get scores high enough to get into dental school. Send a message and I will be happy to help you. You can also join our study group and get some expert advice.I took a practice RC section and did awful . I have heard most people say that you can't improve this section because reading comprehension skill have been developing for years.