And the policeman says, "Did you know
you were going 85 miles PER hour?"
The Big Bang Theory Season 10, Episode 21
of 4.6 yoctometers
PER femtosecond.
The Big Bang Theory Season 5, Episode 18
has to be four revolutions PER second.
The Big Bang Theory Season 10, Episode 20
Well, no, not PER se, but...
The Big Bang Theory Season 4, Episode 1
Per our roommate agreement,
kindly refrain from raucous laughter...
The Big Bang Theory Season 4, Episode 24