The number of years it will take you to have completed studied an organism that has a life cycle of 10 years, is 15 or more than that. This is because you cannot just easily derived to a conclusion without controlling the environmental aspects of the experiments.
It covers a more understandable distance that can be determined by a more reasonable unit of measure.
It would be air hose I say
You can write things down, read the material out loud, and read and reread your materials until you pretty much memorize it
