#include <bits/stdc++.h>
using namespace std;
#define FO(x) freopen(#x".in","r",stdin),freopen(#x".out","w",stdout)
#define fo(i,j,k) for(int i=(j),end_i=(k);i<=end_i;i++)
#define fd(i,j,k) for(int i=(j),end_i=(k);i>=end_i;i--)
#define debug(x) cerr<<#x<<"="<<x<<endl
#define all(x) (x).begin(),(x).end()
#define cle(x) memset(x,0,sizeof(x))
#define ll long long
#define ull unsigned ll
#define db double
#define lb long db
#define pb push_back
#define mp make_pair
#define fi first
#define se second
inline ll read()
{
	ll x=0; char ch=getchar(); bool f=0; 
	for(;ch<'0'||ch>'9';ch=getchar()) if(ch=='-') f=1;
	for(;ch>='0'&&ch<='9';ch=getchar()) x=(x<<3)+(x<<1)+(ch^48);
	return f?-x:x;
}

const ll mod = 1e9 + 7;
inline ll Pow(ll x,ll y) {
    ll ans = 1;
    for(; y; y >>= 1, x = x * x % mod)
        if(y & 1)
            ans = ans * x % mod;
    return ans;
}
inline ll Add(ll x,ll y) {
    x += y;
    return (x >= mod) ? x - mod : x;
}
inline ll Dec(ll x,ll y) {
    x -= y;
    return (x < 0) ? x + mod : x;
}
inline ll Mul(ll x,ll y) {
    return 1ll * x * y % mod;
}
const int N=1000010;
const int M=20;
const int inf=2e9;
const ll Inf=4e18;
int lg[N];

int top[2],s[2][N];
ll w[2][N];
ll ans;
namespace T2{
	ll ans;
	int ne[N],head[N],ver[N],tot=1,dep[N];
	int dfn[N],tim,low[N];
	ll val[N],dis[N];
	int cnt,fir[N],f[M][N];
	inline void add(ll z,int y,int x)
	{
		ver[++tot]=y; val[tot]=z; ne[tot]=head[x]; head[x]=tot;
		ver[++tot]=x; val[tot]=z; ne[tot]=head[y]; head[y]=tot;
	}
	inline void _add(int x,int y,ll z)
	{
		ver[++tot]=y; val[tot]=z; ne[tot]=head[x]; head[x]=tot;
	}
	void dfs(int u,int pre)
	{
		dep[u]=dep[pre]+1; f[0][++cnt]=u; fir[u]=cnt;
		dfn[u]=++tim;
		for(int i=head[u],v;i;i=ne[i])
			if((v=ver[i])!=pre)
			{
				dis[v]=dis[u]+val[i];
				dfs(v,u);
				f[0][++cnt]=u;
			}
		low[u]=tim;
	}
	inline int cmp(int x,int y){return dep[x]<dep[y]?x:y;}
	void pre(int n)
	{
		dfs(1,0);
		fo(j,1,M-1)
			fo(i,1,cnt+1-(1<<j))
				f[j][i]=cmp(f[j-1][i],f[j-1][i+(1<<(j-1))]);
        fo(i,1,n) head[i] = 0;
		tot=1;
	}
	inline int lca(int x,int y)
	{
		x=fir[x]; y=fir[y];
		if(x>y) swap(x,y);
		int k=lg[y-x+1];
		return cmp(f[k][x],f[k][y-(1<<k)+1]);
	}
	int b[N],m,opt[N],st[N];
	ll va[N];
	bool vis[N];
	int siz[N][2];
    ll d1[N][2], d2[N][2], d3[N][2];
	void dfs(int u)
	{
        fo(j,0,1)
            d1[u][j] = d2[u][j] = d3[u][j] = siz[u][j] = 0;
        if (vis[u]) {
            d1[u][opt[u]] = va[u] % mod;
            d2[u][opt[u]] = dis[u] % mod;
            d3[u][opt[u]] = 1ll * (va[u] % mod) * (dis[u] % mod) % mod;
            siz[u][opt[u]] = 1;
        }
		for(int i=head[u],v;i;i=ne[i])
		{
			v=ver[i];
			dfs(v);
            fo(j,0,1)
                ans = (ans + 
                    d3[u][j] * siz[v][1-j] + d2[u][j] * d1[v][1-j] +
                    d3[v][j] * siz[u][1-j] + d2[v][j] * d1[u][1-j] +
                    -2ll * (dis[u] % mod) * ((d1[u][j] * siz[v][1-j] + d1[v][j] * siz[u][1-j]) % mod) % mod
                    ) % mod;
            fo(j,0,1)
                siz[u][j] += siz[v][j],
                d1[u][j] = Add(d1[u][j], d1[v][j]),
                d2[u][j] = Add(d2[u][j], d2[v][j]),
                d3[u][j] = Add(d3[u][j], d3[v][j]);
		}
	}
	inline void build_tree()
	{
		m=0;
		fo(j,0,1) {
            fo(i,1,top[j]) b[++m]=s[j][i];
        }
		sort(b+1,b+m+1,[&](const int &x,const int &y){return dfn[x]<dfn[y];});
		fo(i,1,m) vis[b[i]]=1;
		fo(j,0,1) fo(i,1,top[j]) opt[s[j][i]]=j;
		fo(j,0,1) fo(i,1,top[j]) va[s[j][i]]=w[j][i];
		fo(i,1,m-1) b[++m]=lca(b[i],b[i+1]);
		sort(b+1,b+m+1,[&](const int &x,const int &y){return dfn[x]<dfn[y];});
		m=unique(b+1,b+m+1)-b-1;
		fo(i,1,m) head[b[i]]=0; tot=1;
		int top=0;
		fo(i,1,m)
		{
			for(;top&&low[st[top]]<dfn[b[i]];--top);
			if(top) _add(st[top],b[i],dis[b[i]]-dis[st[top]]);
			st[++top]=b[i];
		}
	}
	void init()
	{
		fo(i,1,m) va[b[i]]=opt[b[i]]=vis[b[i]]=head[b[i]]=0;
		m=0; tot=1;
	}
	inline ll solve() {
        ans = 0;
		build_tree();
		dfs(b[1]);
		init();
		return ans;
	}
    inline void clear(int n) {
        cnt = tim = 0;
        fo(i,1,n) head[i] = dfn[i] = low[i] = 0;
        tot = 1;
    }
}
int n;
namespace T1{
	int pre_n;
	int ne[N],head[N],ver[N],tot=1;
	ll val[N];
	bool vis[N];
	inline void add(int x,int y,ll z)
	{
		ver[++tot]=y; val[tot]=z; ne[tot]=head[x]; head[x]=tot;
		ver[++tot]=x; val[tot]=z; ne[tot]=head[y]; head[y]=tot;
	}
	vector<int> son[N]; ll value[N];
	void dfs(int u,int pre)
	{
		for(int i=head[u],v;i;i=ne[i])
			if((v=ver[i])!=pre)
			{
				dfs(v,u);
				son[u].pb(v); value[v]=val[i];
			}
	}
	void rebuild()
	{
		dfs(1,0);
		fo(i,1,n) head[i]=0;
		tot=1;
		int N=n,w[2],d=0;
		for(int i=1;i<=N;i++)
			if(son[i].size()<=2) for(auto v:son[i]) add(i,v,value[v]);
			else
			{
				w[0]=++N; w[1]=++N;
				add(i,w[0],0); add(i,w[1],0);
				for(auto v:son[i])
				{
					d=1-d; son[w[d]].pb(v);
				}
			}
		n=N;
	}
	int siz[N],minn,edge;
	ll dis[N];
	void getroot(int u,int pre,int s)
	{
		siz[u]=1;
		for(int i=head[u],v,tmp;i;i=ne[i])
			if((v=ver[i])!=pre&&!vis[i>>1])
			{
				getroot(v,u,s);
				siz[u]+=siz[v];
				tmp=max(siz[v],s-siz[v]);
				if(tmp<minn) minn=tmp,edge=i;
			}
	}
	int now;
	void getdis(int u,int pre)
	{
		if(u<=pre_n)
		{
			++top[now];
			s[now][top[now]]=u;
			w[now][top[now]]=dis[u];
		}
		for(int i=head[u],v;i;i=ne[i])
			if(!vis[i>>1]&&(v=ver[i])!=pre)
			{
				dis[v]=dis[u]+val[i];
				getdis(v,u);
			}
	}
	void divide(int u,int s)
	{
		minn=inf; getroot(u,0,s);
		if(minn>=inf) return;
		int j=edge,s1=siz[ver[j]],s2=s-s1;
		vis[j>>1]=1; top[0]=top[1]=0;
		dis[ver[j]]=dis[ver[j^1]]=0;
        dis[ver[j]]=val[j];
		now=0; getdis(ver[j],0);
		now=1; getdis(ver[j^1],0);
		ans = (ans + T2::solve() + mod) % mod;
		fo(j,0,1) fo(i,1,top[j]) w[j][i]=0;
		divide(ver[j],s1); divide(ver[j^1],s2);
	}
	inline void work()
	{
		pre_n=n;
		rebuild();
		divide(1,n);
	}
    void clear() {
        fo(i,1,n)
            son[i].clear(), head[i] = 0;
        fo(i,1,tot) vis[i>>1] = 0;
        tot = 1;
    }
}

void Solve() {
	n=read();
	fo(i,2,n<<1) lg[i]=lg[i>>1]+1;
	int x,y; ll z;
	fo(i,2,n) x=read(),y=read(),z=read(),T1::add(x,y,z);
	fo(i,2,n) T2::add(read(),read(),read());
	T2::pre(n); T1::work();
    ans = (ans * 2 % mod + mod) % mod;
	printf("%lld\n", ans);
    T1::clear(); T2::clear(n);
}

int main() {
    int T = read();
    for (;T--;) {
        ans = 0;
        Solve();
    }
	return 0;
}