Most of the default questions of the survey can be deactivated (not deleted), if you don't feel that they serve a purpose in the survey widget on your website.
From the “Survey” section, find your question: you will be able to check its “status”, in other words, whether the question is “active” (running on at least one of your survey) or “inactive” (not showing on any of your surveys).
In order to deactivate a specific question, find it and click on the dots on the right. Then click on “Deactivate” and the question will be moved down the page to "inactive question" from where you may activate it again whenever you feel like it.
From the same dropdown menu, you will also be able to edit your question (this is valid only for your own custom questions, you cannot modify UserReport pre-built ones).
You can also choose to delete questions permanently or even hide the results of some specific questions.
This means your users, when filling in the survey won’t see what other users voted for.