When you dismiss an activity, it is hidden from the Quick Eval list, but won't affect the activity. A dismissed activity is still available for evaluation from its own tool (Assignments, Quizzes, Discussions).
To Dismiss Activities
From your course navbar, click Course Tools → Course Admin → Quick Eval.
From the View by options, click the Activities tab.
Hover over the activity you want to dismiss and click More Actions → Dismiss until.
Select one of the following:
A specific date and set how long you want to dismiss the activity for
Dismiss Until Next Submission
Select Dismiss Activity.
The activity remains dismissed until the selected condition is met, or you manually restore it using the ellipsis icon in Quick Eval.
To Restore Activities
You can also restore activities that have been hidden.
From your course navbar, click Quick Eval.
Click Quick Eval More Actions and select Dismissed activities.
Select the check box of the item you want to restore and click Restore.