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

using namespace std;

const long long mod = 1000000007;
long long n;
long long a[1200];
long long ans;
long long ksm ( 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 % mod;
}
long long inv ( long long x ) {
    return ksm ( x , mod - 2 );
}
void work () {
    long long i;
    scanf ( "%lld" , &n );
    for ( i = 1 ; i <= n ; i++ ) {
        scanf ( "%lld" , &a[i] );
    }
    ans = a[1] / 2;
    for ( i = 2 ; i <= n ; i++ ) {
        //ans = (ans + a[i] * inv(a[i-1]) + mod - 1 ) % mod;
        ans = (ans + a[i] * inv(4) % mod + mod - a[i-1] * inv (4) % mod) % mod;
    }
    printf ( "%lld\n" , ans % mod );
}
int main () {
    int t;
    scanf ( "%d" , &t );
    while ( t-- ) work ();
    return 0;
}