#include <cstdio>
#include <cstdlib>
#include <cstring>

using namespace std;
#define MOD 1000000007

long long frac[200010];
int T, N, ai, ans1, ans2, inv[200010];

long long C(int n, int m) {
    return frac[n] * inv[n - m] % MOD * inv[m] % MOD;
}

long long power(long long x, int y) {
    long long ans = 1;
    while (y) {
        if (y & 1)
            ans = ans * x % MOD;
        x = x * x % MOD;
        y /= 2;
    }
    return ans;
}

int main() {
    frac[0] = inv[0] = 1;
    for (int i = 1; i < 200010; ++i) {
        frac[i] = frac[i - 1] * i % MOD;
        inv[i] = power(frac[i], MOD - 2);
    }
    scanf("%d", &T);
    while (T--) {
        scanf("%d", &N);
        N = N * 2;
        ans1 = ans2 = 1;
        for (int i = 0, cnt = 0, last = 0; i <= N; ++i) {
            if (i < N) {
                scanf("%d", &ai);
                if (i == 1)
                    last = ai;
                if (last == ai)
                    ++cnt;
            }
            if (last != ai || i == N) {
                if (i % 2 == 0)
                    if (cnt % 2 == 0)
                        ans1 = ans1 * C(cnt, cnt / 2) % MOD; else
                        ans1 = (ans1 * C(cnt, cnt / 2 + 1) % MOD + ans2 * C(cnt, cnt / 2) % MOD) % MOD; else
                    if (cnt % 2 == 1) {
                        ans2 = ans1 * C(cnt, cnt / 2 + 1) % MOD;
                        ans1 = ans1 * C(cnt, cnt / 2) % MOD;
                    } else {
                        int t1 = ans1, t2 = ans2;
                        ans1 = (t1 * C(cnt, cnt / 2) % MOD + t2 * C(cnt, cnt / 2 - 1) % MOD) % MOD;
                        ans2 = (t1 * C(cnt, cnt / 2 + 1) % MOD + t2 * C(cnt, cnt / 2) % MOD) % MOD;
                    }
                last = ai;
                cnt = 1;
            }
        }
        printf("%d\n", ans1);
    }
    return 0;
}