While PDF and Word Documents cannot be directly uploaded on Extempore, as of January 2021, image uploads are much larger than in the past. This makes it possible to take a screenshot of a PDF or Word Document and upload it as an image prompt on Extempore.
(Mobile App Example)
If you want your students to see written text as a prompt, the best way is to copy and paste the content of the word document into the question prompt. That will allow Extempore to resize the text and make it scrollable in all screens.