
You really want to CHALLENGE yourself,
you could learn to speak Hindi.
The Big Bang Theory Season 10, Episode 22

All right, we've defeated the first CHALLENGE.
The Big Bang Theory Season 8, Episode 19

I always got stuck on
the first CHALLENGE--
The Big Bang Theory Season 7, Episode 3

Challenge them again.
The Big Bang Theory Season 10, Episode 22

She has set me a CHALLENGE
Vikings Season 1, Episode 9