#define IOS ios_base::sync_with_stdio(0); cin.tie(0);

 #include <cstdio>//sprintf islower isupper

 #include <cstdlib>//malloc  exit strcat itoa system("cls")

 #include <iostream>//pair

 #include <fstream>//freopen("C:\\Users\\13606\\Desktop\\Input.txt","r",stdin);

 #include <bitset>

 //#include <map>

 //#include<unordered_map>

 #include <vector>

 #include <stack>

 #include <set>

 #include <string.h>//strstr substr strcat

 #include <string>

 #include <time.h>// srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;

 #include <cmath>

 #include <deque>

 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less

 #include <vector>//emplace_back

 //#include <math.h>

 #include <cassert>

 #include <iomanip>

 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor

 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)

 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation

 //******************

 clock_t __START,__END;

 double __TOTALTIME;

 void _MS(){__START=clock();}

 void _ME(){__END=clock();__TOTALTIME=(double)(__END-__START)/CLOCKS_PER_SEC;cout<<"Time: "<<__TOTALTIME<<" s"<<endl;}

 //***********************

 #define rint register int

 #define fo(a,b,c) for(rint a=b;a<=c;++a)

 #define fr(a,b,c) for(rint a=b;a>=c;--a)

 #define mem(a,b) memset(a,b,sizeof(a))

 #define pr printf

 #define sc scanf

 #define ls rt<<1

 #define rs rt<<1|1

 typedef pair<int,int> PII;

 typedef vector<int> VI;

 typedef unsigned long long ull;

 typedef long long ll;

 typedef double db;

 const double E=2.718281828;

 const double PI=acos(-1.0);

 const ll INF=(1LL<<);

 const int inf=(<<);

 const double ESP=1e-;

 const int mod=(int)1e9+;

 const int N=(int)5e5+;

 int fa[N];

 int SZ[N];

 int Find(int x)

 {

     return (x==fa[x])?x:(fa[x]=Find(fa[x]));

 }

 vector<vector<int> >G(N);

 pair<ll,int> a[N];

 bool vis[N];

 void solve()

 {

     int n;

     sc("%d",&n);

     for(int i=;i<=n;++i)fa[i]=i,sc("%lld",&a[i].first),a[i].second=i,G[i].clear();

     for(int i=;i<=n-;++i)

     {

         int u,v;

         sc("%d%d",&u,&v);

         G[v].push_back(u);

         G[u].push_back(v);

     }

     sort(a+,a++n);

     mem(vis,);

     for(int i=;i<=n;++i)SZ[i]=;

     ll ans=;

     for(int i=;i<=n;++i)

     {

         int now=a[i].second;

         vis[now]=;

         int sz=G[now].size();

         for(int j=;j<sz;++j)

         {

             int to=G[now][j];

             if(vis[to])

             {

                 ans=(ans+a[i].first*SZ[now]%mod*SZ[Find(to)]%mod)%mod;

                 SZ[now]+=SZ[Find(to)];

                 fa[Find(to)]=Find(now);

             }

         }

     }

 //    cout<<ans<<endl;

     mem(vis,);

     for(int i=;i<=n;++i)SZ[i]=;

     for(int i=;i<=n;++i)fa[i]=i;

     for(int i=n;i>=;--i)

     {

         int now=a[i].second;

         vis[now]=;

         int sz=G[now].size();

         for(int j=;j<sz;++j)

         {

             int to=G[now][j];

             if(vis[to])

             {

                 ans=(ans-a[i].first*SZ[now]%mod*SZ[Find(to)]%mod+mod)%mod;

                 SZ[now]+=SZ[Find(to)];

                 fa[Find(to)]=Find(now);

             }

         }

     }

     pr("%lld\n",ans);

 }

 int main()

 {

     int T;

     sc("%d",&T);

     while(T--)solve();

     return ;

 }

 /**************************************************************************************/