Answer:
Pair 1 and 2, pair 2 and 3, pair 3 and 4, pair 4 and 1
Explanation:
Any pair of numbers that isn't diagonal from each other can be a pair. A linear pair is simply two angles that add up to 180°, so if you have a completely straight line with a ray coming up from it at any angle, that's a linear pair. Choose any two of the four options I gave you.