#include<bits/stdc++.h>
using namespace std;

const int P = 1e9 + 7 , iv4 = (P + 1) / 4;
int poww(long long a , int b){int tms = 1; while(b){if(b & 1) tms = tms * a % P; a = a * a % P; b >>= 1;} return tms;}
int T , N , A[1003];

int main(){
    for(cin >> T ; T ; --T){
        cin >> N; for(int i = 1 ; i <= N ; ++i) cin >> A[i];
        int cnt = A[1] / 2;
        for(int i = 2 ; i <= N ; ++i)
            if(A[i] != A[i - 1])
                cnt = (cnt + (A[i] - A[i - 1]) * 1ll * iv4) % P;
        cout << cnt << endl;
    }
    return 0;
}