I'm not sewing at the moment, still, so I wouldn't be entering anything. But first I had to look up duvet cover, which of course is a covering for a duvet, stoopid gurl. THEN I needed to look up what a duvet is.
OK, something similar to a down blanket. I think some people here put covers on those but no one I know. We tend to use quilts, comforters or bedspreads as a topping layer on our beds, often over other blankets and always a top sheet as the bottom layer of all of that.
Then I looked up airing cupboard. We don't tend to have those, at least not my part of the US. I've never seen one and I've been in a lot of old houses. California we tend to have attached garages. The water heater is out there.
TSP is such an educational place.