#include <bits/stdc++.h>
#define inf 0x3f3f3f3f
#define MOD 1000000007
#define inv4 250000002

using namespace std;

typedef long long ll;
typedef double db;

ll pow_mod(ll x,int k) {
  ll ans=1;
  while (k) {
      if (k&1) ans=ans*x%MOD;
      x=x*x%MOD;
      k>>=1;
  }
  return ans;
}

int num[15];

int main() {
  int cases;
  scanf("%d",&cases);
  for(;cases;cases--) {
      int n;
      scanf("%d",&n);
      ll ans=0;
      for(int i=1;i<=n;i++) {
      scanf("%d",&num[i]);
      ans=(ans+(num[i]>>1))%MOD;
    }
    for(int i=2;i<=n;i++) ans=(ans-(ll)(num[i-1]+num[i])%MOD*inv4%MOD+MOD)%MOD;
    printf("%lld\n",ans);
  }
  return 0;
}