#include<bits/stdc++.h>
#define LL long long
#define P pair<int,int>
#define fi first
#define se second
#define fr(x) freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);
using namespace std;
inline string rds()
{
	string x="";char ch=getchar();
	while(ch<'a'||ch>'z') ch=getchar();
	while(ch>='a'&&ch<='z') x+=ch,ch=getchar();
	return x;
}
inline int rd()
{
	int x=0;char ch=getchar();
	while(ch<'0'||ch>'9') ch=getchar();
	while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
	return x;
}
const int N=1e6+5,mod=998244353;
int T,n,m,q,pw[N],a[N];string c[N];
inline int md(int x){return x>=mod?x-mod:x;}
int main()
{
	T=rd();
	while(T--)
	{
		n=rd(),m=rd();for(int i=1;i<=n;i++) c[i]=rds();q=rd();
		for(int i=pw[0]=1;i<=m;i++) pw[i]=28ll*pw[i-1]%mod;
		for(int i=1;i<=n;i++)
		{
			int S=0;
			for(int j=0;j<m;j++) S=(S+1ll*pw[m-1-j]*(c[i][j]-'a'+1))%mod;
			a[i]=S;
			for(int j=0;j<m-1;j++)
			{
				S=(S-1ll*pw[m-1]*(c[i][j]-'a'+1))%mod;S=md(S+mod);
				S=(28ll*S+(c[i][j]-'a'+1))%mod;a[i]=min(a[i],S);
			}
		}int x,y;
		while(q--) x=rd(),y=rd(),puts((a[x]==a[y])?"Yes":"No");	
	}
	return 0;
}