#include <bits/stdc++.h>

#define x first
#define y second
#define el '\n'
#define debug(x) cout << #x << ": " << x << el
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int N = 3e5 + 10, INF = 0x3f3f3f3f, mod = 1e9 + 7, MAXP = 18;

ll qmi(ll a, ll b) {
    ll res = 1;
    while (b) {
        if (b & 1) res = res * a % mod;
        a = a * a % mod;
        b >>= 1;
    }
    return res;
}

ll inv(ll a) { return qmi(a, mod - 2); }

void inc(ll &a, ll b) {
    a += b;
    if (a >= mod) a -= mod;
}

void dec(ll &a, ll b) {
    a -= b;
    if (a < 0) a += mod;
}

ll add(ll a, ll b) {
    a += b;
    return a >= mod ? a - mod : a;
}

ll del(ll a, ll b) {
    a -= b;
    return a < 0 ? a + mod : a;
}

ll fac[N], ifac[N];

ll ans;
int n, m, k;
vector<int> G[N], ban[N];
int pa[N][MAXP], dep[N];
unordered_set<int> S[N];

void dfs0(int u, int fa) {
    pa[u][0] = fa, dep[u] = dep[fa] + 1;
    for (int i = 1; i < MAXP; ++i) pa[u][i] = pa[pa[u][i - 1]][i - 1];
    for (int v: G[u]) 
        if (v != fa) {
            dfs0(v, u);
        }
}

int lca(int a, int b) {
    if (dep[a] < dep[b]) swap(a, b);
    for (int i = MAXP - 1; i >= 0; --i) if (dep[pa[a][i]] >= dep[b]) a = pa[a][i];
    if (a == b) return a;
    for (int i = MAXP - 1; i >= 0; --i) 
        if (pa[a][i] != pa[b][i]) 
            a = pa[a][i], b = pa[b][i];
    return pa[a][0];
}

ll binom(ll a, ll b) {
    return fac[a] * ifac[b] % mod * ifac[a - b] % mod;
}

void dfs(int u, int fa) {
    int sn = u;
    for (int v: G[u]) {
        if (v == fa) continue;
        dfs(v, u);
        if (S[v].size() > S[sn].size()) sn = v;
    }
    S[u].swap(S[sn]);
    for (int v: G[u]) {
        if (v == fa) continue;
        for (int j: S[v]) S[u].insert(j);
        S[v].clear();
    }
    for (int i: ban[u]) {
        S[u].erase(i);
        if (S[u].size() >= k - 1) inc(ans, binom(S[u].size(), k - 1));
    }
}

void solve() {
    ans = 0;
    cin >> n >> m >> k;
    fac[0] = 1;
    for (int i = 1; i <= n; ++i) fac[i] = fac[i - 1] * i % mod;
    ifac[n] = inv(fac[n]);
    for (int i = n; i; --i) ifac[i - 1] = ifac[i] * i % mod;
    for (int i = 1; i <= n; ++i) {
        G[i].clear(), S[i].clear(), ban[i].clear();
    }
    for (int i = 1; i < n; ++i) {
        int a, b; cin >> a >> b;
        G[a].emplace_back(b), G[b].emplace_back(a);
    }
    dfs0(1, 0);
    for (int i = 0; i < m; ++i) {
        int a, b; cin >> a >> b;
        S[a].insert(i), S[b].insert(i);
        ban[lca(a, b)].emplace_back(i);
    }
    // for (int i = 1; i <= n; ++i) cout << sn[i] << " \n"[i == n];
    dfs(1, 0);
    cout << ans << el;
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    int tcase = 1;
    cin >> tcase;
    while (tcase--) solve();
}