介绍:
-Sheldon: There are a lot of advantages to buying in bulk. For example, I noticed that you purchase your tampons one-month supply at a time.
-Penny：What?
-Sheldon: Think about it. It's a product that doesn't spoil and you're going to need them for at least the next 30 years.
-Penny：You want me to buy 30 years worth of tampons?
-Sheldon: Well, 30, 35. When did your mother go into menopause?
-Penny：Okay. I'm not talking about this with you.
-Sheldon: Oh, Penny, this is a natural human process, and we're talking about statistically significant savings. Now, if you assume 15 tampons per cycle and a 28-day cycle...Are you fairly regular?
