/*
ID: espr1t
TASK: 
KEYWORDS: 
*/

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;
FILE *in; FILE *out;

const int MAX = 2000002;
const int MOD = 1000000007;

int fact[MAX];

long long fastPow(long long num, long long pwr) {
    long long ret = 1;
    while (pwr) {
        if (pwr & 1LL)
            ret = (ret * num) % MOD;
        num = (num * num) % MOD;
        pwr /= 2LL;
    }
    return ret;
}

long long comb(int n, int k) {
    long long ret = fact[n];
    ret = (ret * fastPow(fact[k], MOD - 2)) % MOD;
    ret = (ret * fastPow(fact[n - k], MOD - 2)) % MOD;
    return ret;
}

long long cat(int n) {
    long long ret = comb(2 * n, n);
    ret = (ret * fastPow(n + 1, MOD - 2)) % MOD;
    return ret;
}

int main(void) {
	in = stdin; out = stdout;
	in = fopen("brackets.in", "rt"); out = fopen("brackets.out", "wt");
	
	fact[0] = 1;
	for (int i = 1; i < MAX; i++)
	    fact[i] = ((long long)fact[i - 1] * i) % MOD;
	
    int numTests;
    fscanf(in, "%d", &numTests);
    for (int test = 0; test < numTests; test++) {
        int k;
        fscanf(in, "%d", &k);
        long long ans = 1, sum = 0;
        for (int i = 0; i < k; i++) {
            int cnt;
            fscanf(in, "%d", &cnt);
            sum += cnt;
            ans = (ans * comb(sum, cnt)) % MOD;
            /*
            ans = (ans * comb(sum, cnt)) % MOD;
            ans = (ans * cat(cnt)) % MOD;
            */
        }
        ans = (ans * cat(sum)) % MOD;
        fprintf(out, "%lld\n", ans);
    }
	
	return 0;
}