♪ The Earth BEGAN to cool
The Big Bang Theory Season 7, Episode 24
# The Earth BEGAN to cool #
The Big Bang Theory Season 11, Episode 10
♪ The autotrophs BEGAN to drool,
Neanderthals developed tools ♪
The Big Bang Theory Season 7, Episode 18
♪ The autotrophs BEGAN to drool,
Neanderthals developed tools ♪
The Big Bang Theory Season 7, Episode 17
♪ The Earth BEGAN to cool
The Big Bang Theory Season 12, Episode 21