The helpful store clerk responds, “Why, it’s a thermos.”
Still curious, the blonde asks, “What does it do?”
“It keeps hot things hot and cold things cold,” replies the clerk.
So she buys one….
The next day, she brings her new thermos to work with her.
Her boss, also a blonde, asks, “What’s that shiny thingy?”
She replies with authority, “It’s a thermos.”
“Oh,” says he, “And what’s it do?”
“Well,” says she, “It keeps hot things hot and cold things cold.”
Then he asks, “So what do you have in there today?”
“Two cups of hot coffee and a Pepsi .”