A garbage truck.
or
Drinking, bathing, washing, swimming, etc.
or
At the Whale-weigh station.
or
If one side has one, the other side has to get one. Once launched, they cannot be recalled. When they land, they screw up everything forever.
or
Five. Four to decide which way the bulb ought to turn, and . . .
or
You're the only bright spot in my life.
or