#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define int long long
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<bool> vb;
typedef tree<pii,null_type,less<pii>,rb_tree_tag,
tree_order_statistics_node_update> oset;
#define fi first
#define se second
#define pb push_back
#define mid (l+r)/2
#define all(x) x.begin(),x.end()
#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)
#define cont(x) for(auto el:x) cout<<el<<' ';cout<<endl;
#define contp(x) for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;
#define sp <<" "<<
#define DEBUG(x) cout<<(#x) sp x<<endl
#define carp(a,b) ((a%MOD)*(b%MOD))%MOD
#define topla(a,b) ((a%MOD)+(b%MOD))%MOD
const int INF=1e18;
const int MAXN=65;
const int MAXK=30;
const int MOD=1e9+7;
int n,m,k;
vi adj[MAXN];
int up[MAXN][MAXK];
int dep[MAXN], p[MAXN];
void dfs(int nd,int ata,int h){
dep[nd]=h;
p[nd]=ata;
for(auto kom:adj[nd]){
if(kom==ata) continue;
dfs(kom,nd,h+1);
}
}
void calc(){
memset(up,-1,sizeof up);
FORE(i,1,n+1){
up[i][0]=p[i];
}
FORE(j,1,MAXK){
FORE(i,1,n+1){
if(up[i][j-1]==-1) break;
up[i][j]=up[up[i][j-1]][j-1];
}
}
}
int lca(int a,int b){
//a altta olan, b üstte olan
if(dep[a]<dep[b]) swap(a,b);
for(int i=MAXK-1;i>=0;i--){
int tt=up[a][i];
if(tt==-1) continue;
if(dep[tt]>=dep[b]) a=tt;
}
if(a==b) return a;
for(int i=MAXK-1;i>=0;i--){
int bir=up[a][i];
int iki=up[b][i];
if(bir==-1 or iki==-1) continue;
if(bir!=iki){
a=bir;
b=iki;
}
}
return up[a][0];
}
int exp(int x,int us){
int res=1;
while(us>0){
if(us&1) res=carp(res,x);
x=carp(x,x);
us/=2;
}
return res;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin>>n>>m>>k;
FOR(i,n-1){
int a,b;
cin>>a>>b;
adj[a].pb(b);
adj[b].pb(a);
}
dfs(1,-1,0);
//FORE(i,1,n+1) cout<<"i" sp i sp dep[i]<<endl;
calc();
while(m--){
int a,b;
cin>>a>>b;
int ata=lca(a,b);
//DEBUG(ata);
int dd=dep[a]+dep[b]-2*dep[ata];
cout<<topla(exp(k,dd),MOD-k)<<endl;
}
}
