causal explanations of
NATURAL phenomena?
The Big Bang Theory Season 12, Episode 18
Yeah! Natural selection at work.
The Big Bang Theory Season 1, Episode 15
When the two of you reach a NATURAL
stopping point, I'd like to have a word.
The Big Bang Theory Season 2, Episode 2
of all the different types
of NATURAL disasters.
The Big Bang Theory Season 11, Episode 13
It could be light bouncing
off a NATURAL object,
The Big Bang Theory Season 12, Episode 20