I'm confused! I wrote "een groot paard..."
Apparently this was wrong. "You used the wrong word.
Een grote knol en een kleine koe" What the hell is a knol, I googled it and the word doesn't even exist..
I would have reported the error message as that sounds like some sort of programing bug. BTW Knol is Dutch for tuber. But, I don't think that is part of the vocabulary in this lesson. So I would still report it as a bug.