could be evidence
of alien CIVILIZATION.
The Big Bang Theory Season 12, Episode 20
They exist in case we ever make contact
with an alien CIVILIZATION.
The Big Bang Theory Season 9, Episode 10
And what a CIVILIZATION is the Greeks'.
The Big Bang Theory Season 4, Episode 21
we're gonna have to
rebuild CIVILIZATION.
The Big Bang Theory Season 12, Episode 14
End of human CIVILIZATION.
Westworld Season 3, Episode 8