Extract sentences

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;


class ExtractSentences
{
    static void Main()
    {
        string text="We are living in a yellow submarine. We don't have anything else. Inside the submarine is very tight. So we are drinking all the day. We will move out of it in 5 days.";
        string word = "in";
        string[] sentences=text.Split('.');

        for (int i = 0; i < sentences.Length; i++)
        {
            if (Regex.Matches(sentences[i],@"\b"+word+@"\b").Count>0)
            {
                Console.WriteLine((sentences[i] + ".").Trim());
            }
        }
    }
}