Uh what the freak is this supposed to mean?

DNA and RNA are polymers of nucleotides. DNA contains deoxyribose; adenine (A) pairs with thymine (T); cytosine (C) pairs with guanine (G) RNA contains ribose and the bases A, C, G, and uracil (U) instead of T. So this is what I'm supposed to learn for my Biology test and it makes no freakin sense I try so hard to pay attention and learn but it goes right over my head like someone is sitting in front of me talking jibberish or something. I have a test in about a week and I'm having a hard time studying I just can't get it in my head what am I supposed to do?