Couple
1. You said this couple lives in your neighborhood.
2. They are the most famous couple in America.
3. Scramble a couple of eggs for me.
4. She called me a couple of days ago.
5. I hope I'm back in a couple of hours.
Pair
1. A customer wants to buy a pair of sandals.
2. You should wear a pair of swimming goggles.
3. These shoes cost two thousand roubles a pair.
4. Pupils at school sit in pairs at desks.
5. I want to give her a pair of gloves.