/*

 ━━━━━┒ギリギリ♂ eye！

 ┓┏┓┏┓┃キリキリ♂ mind！

 ┛┗┛┗┛┃＼○／

 ┓┏┓┏┓┃ /

 ┛┗┛┗┛┃ノ)

 ┓┏┓┏┓┃

 ┛┗┛┗┛┃

 ┓┏┓┏┓┃

 ┛┗┛┗┛┃

 ┓┏┓┏┓┃

 ┛┗┛┗┛┃

 ┓┏┓┏┓┃

 ┃┃┃┃┃┃

 ┻┻┻┻┻┻

 */

 #include <algorithm>

 #include <iostream>

 #include <iomanip>

 #include <cstring>

 #include <climits>

 #include <complex>

 #include <fstream>

 #include <cassert>

 #include <cstdio>

 #include <bitset>

 #include <vector>

 #include <deque>

 #include <queue>

 #include <stack>

 #include <ctime>

 #include <set>

 #include <map>

 #include <cmath>

 using namespace std;

 #define fr first

 #define sc second

 #define cl clear

 #define BUG puts("here!!!")

 #define W(a) while(a--)

 #define pb(a) push_back(a)

 #define Rint(a) scanf("%d", &a)

 #define Rll(a) scanf("%lld", &a)

 #define Rs(a) scanf("%s", a)

 #define Cin(a) cin >> a

 #define FRead() freopen("in", "r", stdin)

 #define FWrite() freopen("out", "w", stdout)

 #define Rep(i, len) for(int i = 0; i < (len); i++)

 #define For(i, a, len) for(int i = (a); i < (len); i++)

 #define Cls(a) memset((a), 0, sizeof(a))

 #define Clr(a, x) memset((a), (x), sizeof(a))

 #define Full(a) memset((a), 0x7f7f, sizeof(a))

 #define lrt rt << 1

 #define rrt rt << 1 | 1

 #define pi 3.14159265359

 #define RT return

 typedef long long LL;

 typedef long double LD;

 typedef unsigned long long ULL;

 typedef pair<int, int> pii;

 typedef pair<string, int> psi;

 typedef map<string, int> msi;

 typedef vector<LL> vl;

 typedef vector<vl> vvl;

 typedef vector<bool> vb;

 typedef struct Query {

     int idx;

     int u, v;

     Query() {}

     Query(int uu, int vv, int ii) : u(uu), v(vv), idx(ii) {}

 }Query;

 typedef struct Edge {

     int v, w;

     Edge() {}

     Edge(int vv, int ww) : v(vv), w(ww) {}

 }Edge;

 typedef struct Ans {

     int idx;

     int ans;

     Ans() {}

     Ans(int aa, int ii) :ans(aa), idx(ii) {}

 }Ans;

 const int maxn = ;

 const int maxm = ;

 int n, m, qcnt, acnt;

 int depth[maxn];

 int in[maxn];

 bool vis[maxn];

 int pre[maxn];

 Query q[maxm];

 Ans ans[maxn];

 vector<Edge> G[maxn];

 int u, v, w;

 int find(int x) {

     return x == pre[x] ? x : pre[x] = find(pre[x]);

 }

 void unite(int x, int y) {

     x = find(x);

     y = find(y);

     if(x != y) pre[y] = x;

 }

 void dfs(int u, int d) {

     // pre[u] = u;

     depth[u] = d;

     Rep(i, G[u].size()) {

         int v = G[u][i].v;

         if(!vis[v]) {

             dfs(v, d+G[u][i].w);

             unite(u, v);

         }

     }

     vis[u] = ;

     Rep(i, qcnt) {

         int uu = q[i].u;

         int vv = q[i].v;

         int idx = q[i].idx;

         if(vis[uu] && vv == u) {

             ans[acnt].idx = idx;

             ans[acnt++].ans = abs(depth[vv] - depth[uu]);

         }

         if(vis[vv] && uu == u) {

             ans[acnt].idx = idx;

             ans[acnt++].ans = abs(depth[uu] - depth[vv]);

         }

     }

 }

 bool cmp(Ans x, Ans y) {

     return x.idx < y.idx;

 }

 int main() {

     // FRead();

     int T;

     Rint(T);

     W(T) {

         Rint(n); Rint(m);

         Cls(vis); Cls(depth); Cls(ans); Cls(G);

         acnt = qcnt = ; Rep(i, n+) G[i].cl(), pre[i] = i;

         Rep(i, n-) {

             Rint(u); Rint(v); Rint(w);

             G[u].push_back(Edge(v, w));

             in[v]++;

         }

         Rep(i, m) {

             Rint(u); Rint(v);

             q[qcnt++] = Query(u, v, i);

         }

         For(i, , n+) if(in[i] == ) dfs(i, );

         sort(ans, ans+acnt, cmp);

         Rep(i, acnt) {

             printf("%d\n", ans[i].ans);

         }

     }

     RT ;

 }