The review units are solely intended to be done with an instructor as an in-lesson activity. These are not intended to be done outside of class as a self-study component. Instructors will be needed to handpick activities based on their student’s weaker points, and give answers/support/feedback on a case-by-case basis.
It is preferred to encourage instructors to be active in choosing which activities and which questions within those activities to pick. Most answers will be quite evident, others will be open-ended. For this reason the answer keys are not provided in the Instructor Guides.