C++ :

#include<bits/stdc++.h>
using namespace std;
long long cs[1000005],a,b,c,n,l,r,ans,bh[1000005],s[1000005];
int main(){
    cin>>n>>a>>b;
    for(int i=1;i<=a;++i)
    {
    	scanf("%lld %lld %lld",&l,&r,&c);
        if(l>r) swap(l,r);
    	cs[l]=(cs[l]%1000000007+c%1000000007)%1000000007;
    	cs[r+1]=(cs[r+1]+1000000007-c%1000000007)%1000000007;
    }
    for(int i=1;i<=n;++i)
    {
    	bh[i]=(bh[i-1]+cs[i])%1000000007;
		//printf("%lld ",bh[i]);
		s[i]=(s[i-1]+bh[i])%1000000007;
    }
    while(b--)
    {
    	scanf("%lld %lld",&l,&r);
        if(l>r) swap(l,r);
    	ans=(s[r]+1000000007-s[l-1])%1000000007;
    	printf("%lld\n",ans);
    }
    return 0;
}