Fill in the blank with the appropriate symbols. In the mathematical system of clock 12 arithmetic, under the operation of addition the set of elements is In the mathematical system of clock 12 arithmetic, under the operation of addition the set of elements is (1,12). {12}. {1,2,3,4,5,6,7,8,9,10,11,12). {0,1,2,3,4,5,6,7,8,9,10,11}.