Drinking, bathing, washing, swimming, etc.
or
So he could grade his eggs.
or
Well, first let's talk about the concept behind this whole "light bulb" thing.
or
Orca-stras
or
At forks in the road.
or
Squeaky clean
or
but unfortunately she'd popped her clogs.
or
Tell him the key signature has 8 sharps.
or
The neutron says "Are you sure?" The proton replies "I'm positive."
or