Two. One to change the bulb, and one to write a song about how good the old light bulb was.
or
they never get old!
or
"Let me see your birth certificate".
or
I don't know. I didn't think sheep could knit
or
Two, one to call Daddy, and one to get the (pick one:) mineral water/Tab.
or
Do you want to grab a bite?
or