#include<bits/stdc++.h>
#define int long long
const int N = 3e5 + 10;
const int Mod = 1e9 + 7;
using namespace std;
vector<int>G[N];
int rev[N][20], dep[N]; 
void dfs (int u, int fa) {
        dep[u] = dep[fa] + 1;
        rev[u][0] = fa;
        for (int i = 1; i <= 19; i ++ ) {
                rev[u][i] = rev[rev[u][i - 1]][i - 1];
        }
        for(auto v: G[u]){
                if(v == fa) continue;
                dfs(v, u);
        }
}
int LCA (int x, int y) {
        if (dep[x] < dep[y]) swap (x, y);
        for (int i = 19; i >= 0; i -- ) {
                if (dep[rev[x][i]] >= dep[y]){
                        x = rev[x][i];
                }
        }
        if (x == y) return x;
        for (int i = 19; i >= 0; i -- ) {
                if (rev[x][i] != rev[y][i]) {
                        x = rev[x][i];
                        y = rev[y][i];
                }
        }
        return rev[x][0];
}
int n, m, k;
int fac[N], nfac[N];
int fpow(int a, int b){
	int x = 1;
	while(b){
		if(b & 1) x = x * a % Mod;
		a = a * a % Mod;
		b >>= 1;
	}
	return x;
}
void init(int num){
	fac[0] = 1; 
	for(int i = 1; i <= num; ++ i) fac[i] = fac[i - 1] * i % Mod;
	nfac[num] = fpow(fac[num], Mod - 2);
	for(int i = num - 1; i >= 0; -- i) nfac[i] = nfac[i + 1] * (i + 1) % Mod;
}
int C(int n, int m){
	if(m > n) return 0;
	return fac[n] * nfac[m] % Mod * nfac[n - m] % Mod;
}
int sum[N], ans, zdd[N];
void clear(){
	for(int i = 1; i <= n; ++ i) G[i].clear();
	for(int i = 0; i <= n; ++ i) sum[i] = 0, zdd[i] = 0;
	ans = 0;
}
void calc(int x, int fa){
	for(auto y: G[x]){
		if(y == fa) continue;
		calc(y, x);
		sum[x] += sum[y];
	}
	ans += (C(sum[x], k) - C(sum[x] - zdd[x], k) + Mod) % Mod;
	// cout << x << " " << sum[x] << " " << zdd[x] << endl;
	ans %= Mod;
}
void solve(){
	cin >> n >> m >> k;
	clear();
	for(int i = 1; i <= n - 1; ++ i){
		int x, y; cin >> x >> y;
		G[x].push_back(y);
		G[y].push_back(x);
	}
	dfs(1, 0);
	for(int i = 1; i <= m; ++ i){
		int x, y;
		cin >> x >> y;
		sum[x] ++; sum[y] ++;
		int ft = LCA(x, y);
		sum[ft] --;	sum[rev[ft][0]]--;
		zdd[ft] ++;
	}
	calc(1, 0);
	cout << ans << endl;
}
signed main(){
	ios::sync_with_stdio(0);
	init(3e5);
	int T; cin >> T;
	while(T--) solve();
}