The decades is accepted on 25Sep17.
I actually typed in "The decades", and it said it was wrong?? The lettering was exactly the same as in the correct answer...? So confusing.
This is likely a bug. Duolingo HQ is looking into it.
This sounds like 'ti-horna' to me. Is that how it's meant to sound?
I'm not hearing an 'h' on my laptop, but the 'orna' part is right, yes.