What you actually pay for something is at least twice the listed price because of the energy， time， money needed to set it up， learn， maintain， repair， and dispose of at the end. Not all prices appear on labels. Actual costs are 2x listed prices.

Understanding how the olfactory system works is not just about understanding smell, but also about understanding how the brain processes information.

当我退役的时候，我希望回头看我走过的路，每一天，我都付出了我的全部。