#include <iostream>
#include <cstring>
#include <string>
using namespace std;
bool b[100005],before[100005],after[100005];
int main(){
	int t;
	cin>>t;
	while(t--){
		int n,q;
		string s;
		cin>>n>>q>>s;
		for(int i=0;i<n;i++){
			if(b[s[i]-'0'])before[i]=1;
			b[s[i]-'0']=1;
		}
		memset(b,0,sizeof b);
		for(int i=n-1;i>=0;i--){
			if(b[s[i]-'0'])after[i]=1;
			b[s[i]-'0']=1;
		}
		while(q--){
			int l,r;
			cin>>l>>r;
			l--;
			r--;
			if(before[l]||after[r])cout<<"Yes"<<endl;
			else cout<<"No"<<endl;
		}
		memset(b,0,sizeof b);
		memset(before,0,sizeof before);
		memset(after,0,sizeof after);
	}
}