# include <bits/stdc++.h>

typedef long long ll;

using namespace std;

const int mod = 1e9 + 7;

int read() {
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-')f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

int gcd(int a, int b) { return (!b) ? a : gcd(b, a % b); }

ll qpow(ll a, ll i) {
    ll res = 1;
    while (i) {
        if (i & 1)res = (res * a) % mod;
        i >>= 1;
        a = (a * a) % mod;
    }
    return res;
}

ll a[1010];

int main() {
    int T = read();
    while (T--) {
        int n = read();
        for (int i = 1; i <= n; i++)a[i] = read();
        ll ans = a[1] / 2;
        for (int i = 1; i < n; i++)
            if (a[i] < a[i + 1]) {
                ans += (a[i + 1] - a[i]) * qpow(4, mod - 2);
                ans %= mod;
            }
        ans = (ans + mod) % mod;
        cout << ans << endl;
    }
    return 0;
}