------
## 最终结论
```python
def min_abs_difference(t, test_cases):
    results = []
    for i in range(t):
        n = test_cases[i][0]
        skills = sorted(test_cases[i][1])
        # Calculate the minimum possible absolute difference
        min_diff = abs(skills[n] - skills[n - 1])
        results.append(min_diff)
    return results

# Example usage:
t = 3
test_cases = [
    (1, [1, 1]),
    (3, [6, 5, 4, 1, 2, 3]),
    (5, [13, 4, 20, 13, 2, 5, 8, 3, 17, 16])
]

print(min_abs_difference(t, test_cases))
```