#include<bits/stdc++.h>
using namespace std;
const int maxn=3e5+10;
const int mod=1e9+7;
vector<int>G[maxn];
int n,m,k,cnt1[maxn],cnt2[maxn],p[maxn][20],dep[maxn];
int ans;

int fac[maxn], ifac[maxn];

inline int fpow(int x, int t = mod - 2) {
	int res = 1;
	for (; t; t >>= 1, x = 1ll * x * x % mod)
		if (t & 1) res = 1ll * res * x % mod;
	return res;
}
int C(int n, int m) {
	if (n < m) return 0;
	return 1ll * fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}
void dfs(int u,int fa)
{
	p[u][0]=fa;
	dep[u]=dep[fa]+1;
	for(auto v:G[u])
	{
		if(v==fa) continue;
		dfs(v,u);
	}
}
void get_ans(int u,int fa)
{
	for(auto v:G[u])
	{
		if(v==fa) continue;
		get_ans(v,u);
		cnt1[u]+=cnt1[v];
		cnt2[u]+=cnt2[v];
	}
	if(cnt1[u]>=k) ans=(1ll*ans+C(cnt1[u],k))%mod;
	if(cnt2[u]>=k) ans=(1ll*ans-C(cnt2[u],k)+mod)%mod;
}
int lca(int x,int y)
{
	if(dep[x]<dep[y])
		swap(x,y);
	int d=dep[x]-dep[y];
	for(int i=19;i>=0;i--)
		if(d&(1<<i))
			x=p[x][i];
	if(x==y) return x;
	for(int i=19;i>=0;i--)
		if(p[x][i]!=p[y][i])
			x=p[x][i],y=p[y][i];
	return p[x][0];
}
int main()
{
	fac[0] = ifac[0] = 1;
	for (int i = 1; i < maxn; ++i) fac[i] = 1ll * fac[i - 1] * i % mod;
	ifac[maxn - 1] = fpow(fac[maxn - 1]);
	for (int i = maxn - 2; i; --i) ifac[i] = 1ll * ifac[i + 1] * (i + 1) % mod;
	int T;
	scanf("%d",&T);
	while(T--)
	{
		scanf("%d%d%d",&n,&m,&k);
		for(int i=1;i<=n;i++)
		{
			cnt1[i]=cnt2[i]=0;
			G[i].clear();
		}
		for(int i=1,u,v;i<n;i++)
		{
			scanf("%d%d",&u,&v);
			G[u].push_back(v);
			G[v].push_back(u);
		}
		dfs(1,0);
		for(int j=1;j<20;j++)
			for(int i=1;i<=n;i++)
				p[i][j]=p[p[i][j-1]][j-1];
		for(int i=1,x,y;i<=m;i++)
		{
			scanf("%d%d",&x,&y);
			int l=lca(x,y);
			cnt1[l]--;
			cnt1[p[l][0]]--;
			cnt1[x]++;
			cnt1[y]++;
			
			cnt2[l]-=2;
			cnt2[x]++;
			cnt2[y]++;
		}
		ans=0;
		get_ans(1,0);
		printf("%d\n",ans);
	}
	return 0;
}