TestTaskClassDataContext db = new TestTaskClassDataContext();
var cityList = from city in db.GetTable<City>()
       join method in db.GetTable<Method>() on city.MethodId equals method.Id
       where (city.Population >= Convert.ToInt32(tbFrom.Text)) &&
                (city.Population <= Convert.ToInt32(tbTo.Text)) &&
                (city.MethodId == Convert.ToInt32(ddlMethod.SelectedItem.Value))
       orderby city.Population ascending
       select new {cName = city.Name, city.Population, mName = method.Name, method.Code};