#include <stdio.h>
#include <algorithm>

using namespace std;

const long long mod=1000000007;
long long n;
long long a[220000];
long long fact[220000],ifac[220000];
long long ans;
long long poww(long long f,long long x){
    long long s=1;
    while(x){
        if(x%2)s=(s*f)%mod;
        f=(f*f)%mod;x=x/2;
    }
    return s;
}
long long C(long long a,long long b){
    return fact[a]*ifac[b]%mod*ifac[a-b]%mod;
}
int main () {
    long long i,t,_t,tmp,cnt;
    scanf("%I64d",&t);
    fact[0]=1;
    for(i=1;i<=200000;i++){
        fact[i]=(fact[i-1]*i)%mod;
    }
    ifac[200000]=poww(fact[200000],mod-2);
    for(i=199999;i>=0;i--)ifac[i]=(ifac[i+1]*(i+1))%mod;
    for(_t=1;_t<=t;_t++){
        scanf("%I64d",&n);
        scanf("%I64d",&a[1]);
        ans=1;
        cnt=1;tmp=0;
        for(i=2;i<=n*2;i++){
            scanf("%I64d",&a[i]);
            if(a[i]!=a[i-1]){
                if(tmp==1){
                    if(i%2==0){
                        ans=(ans*(C(cnt,cnt/2)+C(cnt,cnt/2+1)))%mod;
                    }
                    else{
                        ans=(ans*C(cnt,cnt/2))%mod;
                    }
                }
                else{
                    if(cnt%2)
                        ans=(ans*(C(cnt,cnt/2)+C(cnt,cnt-cnt/2)))%mod;
                    else ans=(ans*C(cnt,cnt/2))%mod;
                }
                if(i%2==0)tmp=1;
                else tmp=0;
                //printf("@@%lld %lld\n",i,ans);
                cnt=1;
            }
            else cnt++;
        }
        if(tmp==1){
            if(i%2==0){
                ans=(ans*(C(cnt,cnt/2)+C(cnt,cnt/2+1)))%mod;
            }
            else{
                ans=(ans*C(cnt,cnt/2))%mod;
            }
        }
        else{
            if(cnt%2)
                ans=(ans*(C(cnt,cnt/2)+C(cnt,cnt-cnt/2)))%mod;
            else ans=(ans*C(cnt,cnt/2))%mod;
        }
        printf("%I64d\n",ans);
    }
    return 0;
}