Woah, big words (joking).
Here are their definitions:
(all from Oxford Languages)
voluminous - (of clothing or drapery) loose and ample or (of writing) very lengthy and full
benign - gentle and kindly.
fortnight - a period of two weeks
prudent - acting with or showing care and thought for the future
Using the definition and context clues, we can determine the answer must be "fortnight."
After being out with a broken leg, a fortnight (2-week period) backlog of assignments had collected in Dave’s desk.
Have a nice day!
I see you have "It's fortnight" at the bottom, which looks to be correct.
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly.
- Heather
