There are 11 pdf files in all, all printed using dopdf - http://www.dopdf.com
The pdfs are based on a Mix and Gap file containing the text, which is also included below (mtx3). This file provides a wide variety of interactive exercises for use with PCs or with an interactive whiteboard. It requires TaskMagic3. If you haven't got TaskMagic3, you can download a 30-day trial from the TaskMagic website (doesn't require registration or anything - just download and install it).
If you've previously trialled TM3 and would like to trial it again, that's now possible. Also, if you'd like to arrange a longer trial period, that's now possible too. See the information at the bottom of the page at http://www.mdlsoft.co.uk/trialdownloads.htm
The screenshot above shows the student front page for the file in TaskMagicPlay. In TaskMagic, each of the little thumbnails links to a different interactive exercise.
And here are the pdf worksheets: