I teach from the same book that you do. Usually, each chapter is four lessons for me: Topic 1, Topic 2, Listening, and Writing. Is there a specific reason they want you to teach those three sections over a period of 6 classes? For the listening, I have enough trouble making it interesting and beneficial enough for one class~!
I haven't looked in the activities book that accompanies the student book because my co-teacher said it was too difficult for the students, but maybe checking out that book would give some ideas for other classes. I would also ask your co-teacher how the previous English teacher allotted time for each section.
The other thing I would suggest is to do project work. Once you have finished your three sections, give them a group project that will take more than one class to complete and present. For example, the listening section of the sports chapter (2?) talks about sports broadcasting. Maybe you could have them create their own news broadcast about different sports and present it to the class? I'm not sure what level your students are or how involved your co-teachers are, which would both affect the outcome of doing something like that.
I wish I could be more help~! Maybe my suggestions will help you think of something better:)