#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
const int N=100010;
ll W[N];
int n;
ll ans;
struct Tree2{
    vector<pair<int,int> > G[N];
    ll sw[N];
    int dfn[N],top[N],siz[N],son[N],dep[N],f[N],num;
    void dfs1(int u,int fa){
        siz[u]=1;
        son[u]=0;
        dep[u]=dep[fa]+1;
        for(auto [v,w]:G[u]){
            if(v==fa)continue;
            sw[v]=(sw[u]+w)%mod;
            f[v]=u;
            dfs1(v,u);
            siz[u]+=siz[v];
            if(siz[v]>siz[son[u]]){
                son[u]=v;
            }
        }
    }
    void dfs2(int u,int topf){
        dfn[u]=++num;
        top[u]=topf;
        if(!son[u])return;
        dfs2(son[u],topf);
        for(auto [v,w]:G[u]){
            if(v==f[u]||v==son[u])continue;
            dfs2(v,v);
        }
    }
    int LCA(int u,int v){
        while(top[u]^top[v]){
            if(dep[top[u]]<dep[top[v]])swap(u,v);
            u=f[top[u]];
        }
        if(dep[u]>dep[v])swap(u,v);
        return u;
    }
    ll totw;
    int totn;
    bool is[N];
    vector<pair<int,ll> > H[N];
    ll sum;
    int gn[N];
    ll gw[N];
    void dfs(int u){
        gn[u]=is[u];
        if(is[u])gw[u]=W[u];
        for(auto [v,w]:H[u]){
            dfs(v);
            gn[u]+=gn[v];
            gw[u]+=gw[v];
            sum=(sum+(gw[v]*(totn-gn[v])+gn[v]*(totw-gw[v]))%mod*w)%mod;
        }
    }
    ll calc(vector<int> a){
        totw=totn=0;
        for(auto x:a){
            ++totn;
            totw=(totw+W[x])%mod;
            is[x]=1;
        }
        sort(a.begin(),a.end(),[&](int x,int y){return dfn[x]<dfn[y];});
        vector<int> bin;
        static int st[N],top;
        st[top=1]=1;
        bin.push_back(1);
        for(auto u:a){
            if(u==1)continue;
            bin.push_back(u);
            int lca=LCA(st[top],u);
            while(dfn[st[top-1]]>=dfn[lca]){
                H[st[top-1]].emplace_back(st[top],sw[st[top]]-sw[st[top-1]]);
                --top;
            }
            if(st[top]^lca){
                bin.push_back(lca);
                H[lca].emplace_back(st[top],sw[st[top]]-sw[lca]);
                st[top]=lca;
            }
            st[++top]=u;
        }
        while(top>1){
            H[st[top-1]].emplace_back(st[top],sw[st[top]]-sw[st[top-1]]);
            --top;
        }
        sum=0;
        dfs(1);
        for(auto x:bin){
            is[x]=0;
            H[x].clear();
            gn[x]=gw[x]=0;
        }
        return sum;
    }
    void clear(int n){
        num=0;
        for(int i=1;i<=n;++i){
            G[i].clear();
        }
    }
    void adde(int u,int v,int w){
        G[u].emplace_back(v,w);
        G[v].emplace_back(u,w);
    }
    void init(){
        for(int i=1;i<n;++i){
            int u,v,w;
            cin>>u>>v>>w;
            adde(u,v,w);
        }
        dfs1(1,0);
        dfs2(1,1);
    }
}T2;
struct Tree1{
    vector<pair<int,int> > G[N];
    bool vis[N];
    void clear(int n){
        for(int i=1;i<=n;++i){
            G[i].clear();
            vis[i]=0;
        }
    }
    void adde(int u,int v,int w){
        G[u].emplace_back(v,w);
        G[v].emplace_back(u,w);
    }
    void init(){
        for(int i=1;i<n;++i){
            int u,v,w;
            cin>>u>>v>>w;
            adde(u,v,w);
        }
    }
    int siz[N],maxp[N];
    int rt;
    void get_root(int u,int fa,int total){
        siz[u]=1;
        maxp[u]=0;
        for(auto [v,w]:G[u]){
            if(v==fa||vis[v])continue;
            get_root(v,u,total);
            siz[u]+=siz[v];
            maxp[u]=max(maxp[u],siz[v]);
        }
        maxp[u]=max(maxp[u],total-siz[u]);
        if(!rt||maxp[u]<maxp[rt]){
            rt=u;
        }
    }
    vector<int> P,Q;
    void dfs1(int u,int fa,ll totw){
        W[u]=totw;
        P.push_back(u),Q.push_back(u);
        for(auto [v,w]:G[u]){
            if(v==fa||vis[v])continue;
            dfs1(v,u,(totw+w)%mod);
        }
    }
    void Div(int u){
        vis[u]=1;
        W[u]=0;
        Q.clear();
        Q.push_back(u);
        for(auto [v,w]:G[u]){
            if(vis[v])continue;
            P.clear();
            dfs1(v,u,w);
            ans=(ans-T2.calc(P))%mod;
        }
        ans=(ans+T2.calc(Q))%mod;
        for(auto [v,w]:G[u]){
            if(vis[v])continue;
            rt=0;
            get_root(v,u,siz[v]);
            Div(rt);
        }
    }
    void Solve(){
        rt=0;
        get_root(1,0,n);
        Div(rt);
    }
}T1;
void Solve(){
    cin>>n;
    ans=0;
    T1.clear(n);
    T2.clear(n);
    T1.init();
    T2.init();
    T1.Solve();
    ans=ans*2%mod;
    cout<<(ans+mod)%mod<<'\n';
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;
    cin>>T;
    while(T--)Solve();
    return 0;
}