
Ninth?
The Big Bang Theory Season 5, Episode 15

did this as our science fair
projects in NINTH grade.
The Big Bang Theory Season 11, Episode 13

In NINTH grade, the girls put
Rogaine in my hand lotion.
The Big Bang Theory Season 5, Episode 11

slip out of the NINTH floor,
and go on a little adventure?
The Big Bang Theory Season 5, Episode 18

Ninth time's the charm.
The Big Bang Theory Season 6, Episode 5