There are a number of ways to navigate through this course.
breadcrumbs at the top right of your screen to the right of the module title.
advance or backtrack through the course activities using the grey buttons at the bottom of each page.
the course menu to the left. Open the menu by clicking on the menu icon on the upper left corner under the CDE logo.
For modules that are organized using books, open the chapter menu by clicking on the blue tab with the white arrow on the upper right corner.