#include <bits/stdc++.h>
#define int long long
#define inf 0x3f3f3f3f
#define re register
#define N 1020030
#define pii pair<int,int>
#define fi first
#define se second
using namespace std;
const int mo=1000000007;
inline int read(){
	int x=0,w=0;char ch=getchar();
	while (!isdigit(ch))w|=ch=='-',ch=getchar();
	while (isdigit(ch))x=(x<<1)+(x<<3)+ch-'0',ch=getchar();
	return w?-x:x;
}

void solve(){
	int n=read(),k=read(),ans=1;
	if (n==k)--k;
	for (int i=1;i<=k;++i)ans=ans*i%mo;
	for (int i=1;i<=n;++i)ans=ans*i%mo;
	for (int i=1;i<=n-k-1;++i)ans=ans*k%mo;
	cout<<ans<<endl;		
}
signed main(){
    int T=read();
    while (T--)solve();
    return 0;
}