Question

a pair of integers whose difference gives zero

Answer 1

1 and 1
2 and 2
3 and 3
And so on...

Answer 2

pair of integers whose difference gives 0 are:-
1 and 1 as 1-1= 0
-1 and -1 as -1 -(-1) = -1+1 = 0
and so on like this.