The Course's Recycle Bin stores material deleted from the course (Assignments, Quizzes, Files/Links, Discussions, Albums, Pages, etc.). You may delete any material in a course you administer. If you've deleted folders of materials, the folders cannot be retrieved; however, the material inside of the folders will be stored in the Recycle Bin.
If you deleted an assignment with grades (scores); restoring the assignment will restored grades in the gradebook. To retrieve deleted material, please view the following: How to Retrieve a Deleted Assignment Video.