Answer:
Have you ever been bitten by a dog?
Step-by-step explanation:
The use of the sentence structure "have+ been+ third form of the verb" is the present perfect form of a sentence. This means that the event or action happened in the past but is important or relevant in the present.
The given question "have you ever ....... by a dog?" will have the "been+ V3" form because it asks any past history of being bitten by a dog. Moreover, the question/ sentence is in the passive voice.
Thus, the correct answer to be used in the given blank will be "been bitten", making the full sentence as
Have you ever been bitten by a dog?