#include <bits/stdc++.h>
 
using namespace std;
 
const int MaxN = (int)4e5 + 10;
const int MOD = (int)1e9 + 7;
const int INF = 1e9;
 
int n, k;
int fact[MaxN], rfact[MaxN], inv[MaxN];
pair < int, int > p[MaxN];
int fenw[MaxN];
 
long long readInt(long long l,long long r,char endd){
	long long x=0;
	int cnt=0;
	int fi=-1;
	bool is_neg=false;
	while(true){
		char g=getchar();
		if(g=='-'){
			assert(fi==-1);
			is_neg=true;
			continue;
		}
		if('0'<=g && g<='9'){
			x*=10;
			x+=g-'0';
			if(cnt==0){
				fi=g-'0';
			}
			cnt++;
			assert(fi!=0 || cnt==1);
			assert(fi!=0 || is_neg==false);
			
			assert(!(cnt>19 || ( cnt==19 && fi>1) ));
		} else if(g==endd){
			if(is_neg){
				x= -x;
			}
			assert(l<=x && x<=r);
			return x;
		} else {
			assert(false);
		}
	}
}
string readString(int l,int r,char endd){
	string ret="";
	int cnt=0;
	while(true){
		char g=getchar();
		assert(g!=-1);
		if(g==endd){
			break;
		}
		cnt++;
		ret+=g;
	}
	assert(l<=cnt && cnt<=r);
	return ret;
}
long long readIntSp(long long l,long long r){
	return readInt(l,r,' ');
}
long long readIntLn(long long l,long long r){
	return readInt(l,r,'\n');
}
string readStringLn(int l,int r){
	return readString(l,r,'\n');
}
string readStringSp(int l,int r){
	return readString(l,r,' ');
}
 

int comb(int n, int k) {
	if (n < k) {
		return 0;
	}
	return 1LL * fact[n] * rfact[k] % MOD * rfact[n - k] % MOD;
}
 
bool cmp(pair < int, int > a, pair < int, int > b) {
	return a.first < b.first || a.first == b.first && a.second > b.second;
}
 
int en;
 
void solve() {
	n = readIntSp(1, 4e5);
	en += n;
	assert (en <= 4e5);
	k = readIntLn(1, n);
	for (int i = 1; i <= n; ++i) {
		p[i].first = readIntSp(1, 1e9);
		p[i].second = readIntLn(p[i].first, 1e9);
	}
	sort(p + 1, p + n + 1, cmp);
	multiset < int > f;
	int bad = 0;
	for (int i = 1; i <= n; ++i) {
		while (!f.empty() && *f.begin() < p[i].first) {
			f.erase(f.begin());
		}
		bad = (bad + 1LL * comb(f.size(), k - 1)) % MOD;
		f.insert(p[i].second);
	}
	printf("%d\n", (comb(n, k) - bad + MOD) % MOD);
}
 
int main() {
//	freopen("input.txt", "r", stdin);
	fact[0] = rfact[0] = 1;
	for (int i = 1; i < MaxN; ++i) {
		inv[i] = i == 1 ? 1 : 1LL * (MOD - MOD / i) * inv[MOD % i] % MOD;
		fact[i] = 1LL * i * fact[i - 1] % MOD;
		rfact[i] = 1LL * inv[i] * rfact[i - 1] % MOD;
	}
	int t = readIntLn(1, 1e3);
	while (t --> 0) {
		solve();
	}
	return 0;
}