Hi @Skylar Wang
Are you using a survey created with MS Forms?
If you are the owner of the team and have the setting "Owners can delete all messages" the three dots will appear, and the form/quick poll can be deleted.
If you are not the Team owner, you will not be able to delete the poll. You can delete the form itself if you go to forms.office.com, log in, go to group forms and delete the form itself. However, this doesn't delete the form in Teams.
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