First, let's take a look at the .make file for this website and learn a little about what each line is telling Drush Make to do. In the dpk directory that you created in a previous step, open the file dpk.make in a text editor of your choice. You should see the following code:
core = 7.x api = 2 ;core ""projects[drupal][type] = "core" projects[drupal][download][type] = "git" projects[drupal][download][tag] = "7.9" projects[drupal][download][url] = "http://git.drupal.org/project/drupal. git"""
The first few lines seem easy enough. We're telling the drush_make command that we're using Drupal 7.0 core, Drush Make API 2, and then giving drush_make a specific method for downloading the Drupal 7.0 core. Notice that, in this instance, we've linked the project to a specific filename and a specific version of Drupal.