Got marked wrong for carrot (singular). But the hover text offers the singular
Moron is one of the few nouns that are generally used in the plural, moron = carrots, the singular is 'moronen'.
As a result when used as an adjective, in this course describing a curry as being 'carrot curry' the plural rather than the singular is used:- 'cyri moron'
That is the reason the apparently singular form was given for 'moron'
Apologies for the confusion there, I've deleted the apparent singular form to avoid misunderstandings.
Thanks for the comment.