There can be only one.
He liked to chop and change !
None. Social scientists do not change light bulbs they search for the root cause as to why the last one went out.
Trick question, they can't change anything.
None they can't change anything.
Because a sheep can hear a zipper from a mile away.
Mee yew!
Mick Jagger sings, "Hey you, get off of my cloud . . ", while the Scottish Highlander yells, "Hey McCloud, get off of my ewe!"