So, Alex,
what's the TOPIC of your dissertation?
The Big Bang Theory Season 6, Episode 3
Hey, here's another possible TOPIC
of conversation.
The Big Bang Theory Season 4, Episode 1
If we're going to change the TOPIC
from jellyfish...
The Big Bang Theory Season 6, Episode 20
New TOPIC, please.
The Big Bang Theory Season 2, Episode 19
...to introduce
an alternate TOPIC of conversation.
The Big Bang Theory Season 4, Episode 7