<p>I have the Biology and US gov crash course and I have to say I dont think biology crash course lived up to its expectations. I had high expectations after reading Direct hits for the SAT and crash course for gov (both by the genious larry kreiger) but the bio crash course is by a different author and it is hard to briefly explain biology and still understand it. The bio crash course is good (and a little confusing) but cliffs and barrons r much better i would give it 3.5 out of 5 stars. I guess I had such high expectations!</p>