The correct answer is, "When covered by
LIQUID sufficient to reduce the coefficient...
The Big Bang Theory Season 2, Episode 5
You see, instead of
using LIQUID helium...
The Big Bang Theory Season 11, Episode 8
It's like a waterfall
of LIQUID gold.
The Big Bang Theory Season 5, Episode 1
[LIQUID SLOSHING]
Breaking Bad Season 2, Episode 4
Floating in a warm pool
of LIQUID
The Big Bang Theory Season 12, Episode 19