A: A theme is selected (or active) if it is raised. A theme may be visible (checked) even if it is not selected. To select the theme, click on the theme name. The rectangle around the theme name will appeared raised when it is active.
Example:
In the following image there are three themes; Riv2m_s, Pop90s, and Envir.
Riv2m_s and Pop90s are both visible in the view (checked), but only the theme Pop90s is active.
