#include <bits/stdc++.h>
 #define ll long long int
 #define mod 1000000007
 
 using namespace std;
int main()
{
	std::ios::sync_with_stdio(false);
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	freopen("error.txt", "w", stderr);
#endif
	int T;
	cin >> T;
	int n;
	while (T--)
	{
		cin >> n;
		ll arr[n];
		ll copg[n], cops[n];
		for (int i = 0; i < n; ++i)
		{
			cin >> arr[i];
			arr[i] %= mod;
		}
		copy(arr, arr + n, copg);
		copy(arr, arr + n, cops);
		sort(copg, copg + n, greater<ll>());
		sort(cops, cops + n);
		ll copmin = (copg[0] - copg[2]) % mod;
		ll compsmin = (cops[2] - cops[0]) % mod;
		ll mi = min(compsmin,	copmin) % mod;
		cout << mi  << endl;
 
	}
}
 

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4
3
1 2 3
4
7 3 7 3
5
3 4 2 1 1
8
3 1 4 1 5 9 2 6