
Penny started taking a CLASS.
She wrote a paper.
The Big Bang Theory Season 6, Episode 6

Hey, what if I took your CLASS?
The Big Bang Theory Season 8, Episode 2

You can get them removed early
but you have to take his CLASS.
The Big Bang Theory Season 2, Episode 7

...and everyone already has a partner
and I'll probably end up failing the CLASS.
The Big Bang Theory Season 6, Episode 8

Did you go to that spin CLASS
on Green Street?
The Big Bang Theory Season 7, Episode 20