#include <bits/stdc++.h>
#define cs const
#define pb push_back
using namespace std;

cs int N = 3e5 + 5; 

cs int mod = 1e9 + 7;
int add(int a, int b) {
    return a + b >= mod ? a + b - mod : a + b; 
}
int dec(int a, int b) {
    return a - b < 0 ? a - b + mod : a - b; 
}
int mul(int a, int b) {
    return 1ll * a * b % mod;
}
int ksm(int a, int b) {
    int c = 1; 
    for(; b; b >>= 1, a = mul(a, a))
    if(b & 1) c = mul(c, a);
    return c; 
}
int n, m, k, T; 
vector <int> e[N];
int mn[20][N], dfn[N], indx, fa[N];
int a[N], b[N];
int fc[N], ifc[N];

int C(int n, int m) {
    if(n < 0 || m < 0 || n < m) return 0;
    return mul(fc[n], mul(ifc[n - m], ifc[m]));
}
void fc_init(int n) {
    fc[0] = ifc[0] = 1;
    for(int i = 1; i <= n; i++) fc[i] = mul(fc[i - 1], i);
    ifc[n] = ksm(fc[n], mod - 2);
    for(int i = n- 1; i; i--) ifc[i] = mul(ifc[i + 1], i + 1);
}

int ck(int x, int y) {
    return dfn[x] < dfn[y] ? x : y; 
}

void dfs(int u, int f) {
    mn[0][indx] = f; 
    fa[u] = f; 
    dfn[u] = ++ indx; 
    for(int v : e[u]) if(v != f) {
        dfs(v, u); 
    }
}
int lca(int u, int v) {
    if(u == v) return u; 
    u = dfn[u], v = dfn[v];
    if(u > v) swap(u, v);
    int x = __lg(v - u); 
    return ck(mn[x][u], mn[x][v - (1 << x)]);
}
int ans = 0; 
void dfs2(int u, int f) {
    for(int v : e[u])
    if(v != f) {
        dfs2(v, u);
        a[u] += a[v];
        b[u] += b[v];
    }
    if(f) {
        ans = dec(ans, C(b[u], k));
    }
    ans = add(ans, C(a[u], k));
}
int main() {
    #ifdef zqj
    freopen("1.in","r",stdin);
    #endif
    ios :: sync_with_stdio(0), cin.tie(0);
    cin >> T; 
    while(T--) {
        cin >> n >> m >> k; 
        fc_init(m);
        for(int i = 1; i < n; i++) {
            int u, v; 
            cin >> u >> v; 
            e[u].pb(v);
            e[v].pb(u);
        }
        dfs(1, 0);
        for(int i = 1; i <= 19; i++)
        for(int j = 1; j + (1 << i) <= n; j++)
        mn[i][j] = ck(mn[i - 1][j], mn[i - 1][j + (1 << (i - 1))]);
        for(int i = 1; i <= m; i++) {
            int u, v; 
            cin >> u >> v; 
            int l = lca(u, v);
            ++ a[u], ++ a[v];
            -- a[l], -- a[fa[l]];
            ++ b[u], ++ b[v], b[l] -= 2; 
        } 
        ans = 0;
        dfs2(1, 0);
        cout << ans << '\n';
        for(int i= 0; i <= n; i++) {
            a[i] = b[i] = 0; 
            e[i].clear();
            dfn[i] = 0; 
        }
        indx = 0; 
    }
}