//https://www.hackerrank.com/contests/hourrank-15/challenges/kittys-calculations-on-a-tree/problem
#include <bits/stdc++.h>
using namespace std;
#define eb emplace_back
using ll = long long;
const int N = 2e5 + 5;
const int LG = 18;
const int MOD = 1e9 + 7;
ll sv[N], sdv[N], res;
int st[N], tp, p[LG][N], d[N];
int tin[N], tim, sp[N];
vector <int> g[N]; bool imp[N];
void madd(ll &x, ll y) {
(x += y) %= MOD;
}
void msub(ll &x, ll y) {
if (((x -= y) %= MOD) < 0)
x += MOD;
}
void clear(vector <int> &v) {
v.clear();
v.shrink_to_fit();
}
void dfs(int u) {
tin[u] = ++tim;
for (int v : g[u]) {
if (v == p[0][u]) continue;
d[v] = d[u] + 1;
p[0][v] = u; dfs(v);
}
}
int lca(int u, int v) {
if (d[u] < d[v]) swap(u, v);
for (int k = LG - 1; ~k; k--)
if (d[p[k][u]] >= d[v])
u = p[k][u];
if (u == v) return u;
for (int k = LG - 1; ~k; k--)
if (p[k][u] != p[k][v]) {
u = p[k][u]; v = p[k][v];
}
return p[0][u];
}
void cal(int u) {
sv[u] = imp[u] ? u : 0;
sdv[u] = sv[u] * d[u] % MOD;
for (int v : g[u]) {
cal(v);
madd(res, sdv[u] * sv[v]);
madd(res, sdv[v] * sv[u]);
msub(res, sv[u] * sv[v]
* 2 % MOD * d[u] % MOD);
madd(sv[u], sv[v]);
madd(sdv[u], sdv[v]);
}
imp[u] = 0; clear(g[u]);
}
int main() {
ios::sync_with_stdio(0);
cin.tie(nullptr);
auto cmp = [&](int x, int y) {
return tin[x] < tin[y];
};
int n, q; cin >> n >> q;
for (int i = 1; i < n; i++) {
int u, v; cin >> u >> v;
g[u].eb(v); g[v].eb(u);
}
d[0] = -1; dfs(1);
for (int k = 1; k < LG; k++)
for (int i = 1; i <= n; i++)
p[k][i] = p[k - 1][p[k - 1][i]];
for (int i = 1; i <= n; i++)
clear(g[i]);
while (q--) {
int k; cin >> k;
for (int i = 0; i < k; i++) {
cin >> sp[i]; imp[sp[i]] = 1;
}
sort(sp, sp + k, cmp);
st[tp = 0] = 1;
for (int i = 0; i < k; i++) {
if (sp[i] == 1) continue;
int r = lca(sp[i], st[tp]);
while (tp && d[r] < d[st[tp - 1]]) {
g[st[tp - 1]].eb(st[tp]); tp--;
}
if (d[r] < d[st[tp]])
g[r].eb(st[tp--]);
if (st[tp] != r) st[++tp] = r;
if (st[tp] != sp[i]) st[++tp] = sp[i];
}
while (tp) {
g[st[tp - 1]].eb(st[tp]); tp--;
}
res = 0; cal(1); cout << res << '\n';
}
}
