One has claws at the end of its paws and one has a pause at the end of its clause
or
First he lies on one side, then he lies on the other.
or
Make sure one is a match!
or
The dentist is taking me out tonight.
or
Only one, but she/he'll have to go out and buy the light bulb adaptor card first, which is extra.
or
Fish and ships.
or