#pragma comment(linker, "/STACK:102412345,102412345")
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<iostream>
#include<cmath>
#include<map>
#include<queue>
#include<vector>


#define mod 1000000007
#define maxn 100010

using namespace std;
void read(int& x){x=0;char ch;
    do ch=getchar();while(ch<'0'||ch>'9');
    do x=x*10+ch-'0',ch=getchar();while(ch<='9'&&ch>='0');
}
int cnt;
struct Edge{int to;Edge *next;
}*E[maxn],Pr[maxn<<1];
void addedge(int u,int v){
    Pr[++cnt].to=v;Pr[cnt].next=E[u];E[u]=&Pr[cnt];
    Pr[++cnt].to=u;Pr[cnt].next=E[v];E[v]=&Pr[cnt];
}
int n,m,size[maxn];
double Ans[maxn];
int V[maxn];
vector<int> has[maxn],chd[maxn];
int Now[maxn];

void dfs(int u,int f){
    size[u]=1;
    for(Edge *P=E[u];P;P=P->next)if(P->to!=f)dfs(P->to,u),size[u]+=size[P->to];
    if(size[u]==1){
        Ans[u]=V[u];has[u].push_back(V[u]);
        return;
    }
    for(Edge *P=E[u];P;P=P->next)if(P->to!=f)chd[u].push_back(P->to);
    for(int i=0;i<chd[u].size();i++)Now[chd[u][i]]=0;
    bool flag=true;
    for(int i=1;i<=size[u];i++){int v=-1;
        for(int j=0;j<chd[u].size();j++)if(Now[chd[u][j]]<has[chd[u][j]].size()&&(v==-1||has[v][Now[v]]>has[chd[u][j]][Now[chd[u][j]]]))v=chd[u][j];
        if(v==-1||(flag&&V[u]<has[v][Now[v]])){
            flag=false;has[u].push_back(V[u]);
        }
        else{
            has[u].push_back(has[v][Now[v]]);Now[v]++;
        }
    }
    if(size[u]&1)Ans[u]=has[u][size[u]/2];else Ans[u]=(double)(has[u][size[u]/2]+has[u][size[u]/2-1])/2;
    for(Edge *P=E[u];P;P=P->next)if(P->to!=f)has[P->to].clear(),chd[P->to].clear();
}


int main(){int T;
    scanf("%d",&T);
    while(T--){
        memset(E,0,sizeof(E));cnt=0;
        scanf("%d%d",&n,&m);
        for(int i=1;i<=n;i++)has[i].clear(),chd[i].clear();
        for(int i=1;i<=n;i++)read(V[i]);
        for(int i=1;i<n;i++){int u,v;
            read(u);read(v);
            addedge(u,v);
        }
        dfs(1,0);
        double ans=0;
        for(int i=1;i<=m;i++){int u;
            read(u);
            ans=fmod(ans*10+Ans[u],mod);
        }
        printf("%.1lf\n",ans);
    }
    return 0;
}