//Δ_1005
#include<iostream>
#include<cstdio>
#include<fstream>
#include<algorithm>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<bitset>
#include<cmath>
#include<cstring>
#include<cstdlib>
using namespace std;
typedef long long LL;
typedef double DB;
const int MO = 1e9+7;
void ad(int&x,int y){
    x+=y;
    if(x>=MO)
        x-=MO;
}
int mul(int x,int y){
    return (LL)x*y%MO;
}
int fpow(int x,int y=MO-2){
    int z=1;
    while(y){
        if(y&1)
            z=mul(z,x);
        x=mul(x,x);
        y>>=1;
    }
    return z;
}
int solve(int x,int y){
    return mul(y,mul(x+y,fpow(y*2)));
}
int main()
{
    int T,n,i,x,y,s;
    cin>>T;
    while(T--){
        cin>>n>>x;
        x/=2;
        s=x;
        for(i=2;i<=n;i=i+1){
            cin>>y;
            y/=2;
            ad(s,y);
            ad(s,MO-solve(x,y));
            x=y;
        }
        cout<<s<<endl;
    }
    return 0;
}