program comnet;
type
        iii=longint;
        bfg=int64;
const
        fi='';
        fo='';
        maxn=100000;
        maxm=1000000;
var
        uu,vv,u,v: array[1..maxm] of iii;
        ww,w: array[1..maxm] of bfg;
        cs,css: array[1..maxm] of iii;
        tt,t: array[1..maxn] of iii;
        n,m,q: iii;
        f1,f2: text;
 
procedure openfile;
begin
        assign(f1,fi); reset(f1);
        assign(f2,fo); rewrite(f2);
end;
 
procedure closefile;
begin
        close(f1); close(f2);
end;
 
procedure inn;
var
        i: iii;
begin
        readln(f1,n,m,q);
        for i:=1 to m do readln(f1,uu[i],vv[i],ww[i]);
        for i:=1 to m do css[i]:=i;
        for i:=1 to n do tt[i]:=i;
end;
 
procedure swap(i,j: iii);
var
        tg: iii;
        tg2: bfg;
begin
        tg:=u[i]; u[i]:=u[j]; u[j]:=tg;
        tg:=v[i]; v[i]:=v[j]; v[j]:=tg;
        tg:=cs[i]; cs[i]:=cs[j]; cs[j]:=tg;
        tg2:=w[i]; w[i]:=w[j]; w[j]:=tg2;
end;
 
procedure qs(l,r: iii);
var
        i,j: iii;
        key: bfg;
begin
        if l>=r then exit;
        i:=l; j:=r; key:=w[i+ random(j-i)+1];
        repeat
                while w[i]<key do inc(i);
                while w[j]>key do dec(j);
                if i<=j then
                  begin
                        swap(i,j);
                        inc(i); dec(j);
                  end;
        until i>j;
        qs(l,j); qs(i,r);
end;
 
function find(x: iii): iii;
begin
        while x<>t[x] do x:=t[x];
end;
 
function union(x,y: iii): boolean;
begin
        x:=find(x); y:=find(y);
        if x=y then exit(false);
        if x>y then t[x]:=y else t[y]:=x;
        exit(true);
end;
 
procedure process;
var
        ii,i,tp,k,s,dinh: iii;
        cp,min,sum: bfg;
begin
        for ii:=1 to q do
          begin
                read(f1,k,s);
                u:=uu; v:=vv; w:=ww; cs:=css; t:=tt;
                for i:=1 to s do
                  begin
                        read(f1,tp,cp);
                        w[tp]:=cp;
                  end;
 
                qs(1,m); min:=0;
                for i:=1 to m do
                  if union(u[i],v[i]) then
                        inc(min,w[i]);
 
                sum:=0; dinh:=1;
                t:=tt;
                for i:=1 to m do
                  if (union(u[i],v[i])) and (cs[i]<>k) then
                    begin
                        inc(dinh);
                        inc(sum,w[i]);
                    end;
 
                if (dinh=n) and (sum=min) then writeln(f2,'YES') else writeln(f2,'NO');
          end;
end;
 
procedure main;
var
        i,test: iii;
begin
        readln(f1,test);
        for i:=1 to test do
          begin
                inn;
                process;
          end;
end;
 
begin
        openfile;
        main;
        closefile;
end.