I'm curious about what declension θορυβος and κοσμος are in Attic Greek. They appear to be second declension (θορυβος, -ου and κοσμος, -ου), but in the Athenaze workbook (which I'm slowly working my way through...), they are listed under first declension nouns.
Is there an error in the book, or are they actually first declension, and if they are, how does that pan out with the other forms (dative, accusative, vocative)?