In a writing class in college, I wrote a paper about the pros and cons of Ethanol, and wrote one sentence which said something along the lines of:  


"Ethanol has the advantage of being grown on farmland, rather than having to dill for the remains of dinosaurs after millions of years of geological forces."  


The teacher flagged the sentence and didn't seem to know that the crude oil we drill for today is the remains of millions year old organisms.