Active Reading in ACT

I am taking the ACT on June 11; however, I am struggling on reading actively on the reading section. I seem to complete the passages and questions in nine minutes each with no mistakes, but that does not allow me to finish and bubble in answers. When I try to finish in eight minutes, I make a lot of mistakes. I take too much time reading since sometimes I won’t understand a sentence and would read it over again and again. When I skim, I sometimes skip over words and end up not understanding. How do I correct this and are there other methods to bring down my time?