None. That's a software problem.
or
At the crystal ball.
or
A coat of arms.
or
One. No, two. No... How many do we have on the truck?
or
Because they don't want to give away their presence.
or
None. Efficiency experts replace only dark bulbs.
or
Do you want to grab a bite?
or
He got caught peeping on a test.
or
Drinking, bathing, washing, swimming, etc.
or
Nothing, it just waved.
or