#include <cstdio>

typedef long long LL;
const int Mod = 1000000007;
const int Inv4 = (Mod + 1) / 4;
const int MN = 15;

int N, S, x;

int main() {
    int Tests;
    scanf("%d", &Tests);
    while (Tests--) {
        scanf("%d", &N), S = 0;
        for (int i = 1; i <= N; ++i) {
            scanf("%d", &x);
            if (i == 1) S += x;
            if (i == N) S += x;
        }
        printf("%lld\n", (LL)S * Inv4 % Mod);
    }
    return 0;
}