#include <iostream>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <queue>
#include <map>
#include <vector>
#define MST(s,q) memset(s,q,sizeof(s))
#define INF 0x3f3f3f3f
 

#define MAXN 50005
#define Lchild id<<1
#define Rchild (id<<1)+1
using namespace std;
struct Query {
    int v, no;
} tmp;
int N, M, T, F[MAXN], dis[MAXN], level[MAXN], vis[MAXN], ans[MAXN];
vector<int>   node[MAXN], w[MAXN];
vector<Query> query[MAXN];

void init() {
    for (int
 
 i = 0; i < MAXN; i++) {
        F[i] = i;
        ans[i] = dis[i] = vis[i] = 0;
        level[i] = 1;
        node[i].clear();
        query[i].clear();
        w[i].clear();
    }
}

int Find (int x) {
    if (F[x] == x) return x;
    return F[x] = Find (F[x]);
}

void Union (int x, int y) {
    int
 
 fa = Find (x), fb = Find (y);
    if (fa == fb) return;
    F[fb] = fa;
}

void LCA (int root, int value) {
    vis[root] = 1;
    dis[root] = value;
    int len = node[root].size();
    for (int i = 0; i < len; i++) {
        int v = node[root][i];
        if (vis[v]) continue;
        LCA (v, value + w[root][i]); // 遞迴子樹
        Union (root, v);
    }
    len = query[root].size();
    for (int i = 0; i < len; i++) {
        int v = query[root][i].v, no = query[root][i].no;
        if (!vis[v]) continue;
        ans[no] = dis[root] + dis[v] - 2 * dis[Find (v)];
    }
}
int main() {
    cin >> T;
    while (T--) {
        cin >> N >> M;
        init();
        int u, v, z;
        for (int i = 1; i < N; i++) {
            scanf ("%d%d%d", &u, &v, &z);
            node[u].push_back (v), w[u].push_back (z);
            node[v].push_back (u), w[v].push_back (z);
        }
        for (int i = 0; i < M; i++) {
            scanf ("%d%d", &u, &v);
            tmp.no = i;
            tmp.v = v, query[u].push_back (tmp);
            tmp.v = u, query[v].push_back (tmp);
        }
        LCA (1, 0);
        for (int i = 0; i < M; i++)
            printf ("%d\n", ans[i]);
    }
}