...the success or failure of the date would
be based on the biochemical REACTION...
The Big Bang Theory Season 1, Episode 3
...or drinking coffee while driving
reduces one's REACTION time...
The Big Bang Theory Season 2, Episode 5
I guess I was hoping for a
different REACTION, but okay.
The Big Bang Theory Season 5, Episode 19
Look at her REACTION
to the good-night kiss.
The Big Bang Theory Season 2, Episode 1