"Our criterion is quality."
Translation:O nosso critério é a qualidade.
I guess the official way is to force a repeat of the question. Sometimes that's hard and sometimes that's easy. This is an easy one: just look up "critério" in your vocab list and do "Practice word" until it comes up again. When I did that, this was the first question I was asked. :-) (I see you have already forced a repeat by redoing the whole lesson; usually the vocab list route is easier.)
Turns out I really needed to redo the whole lesson, unfortunately. But thanks for the tip! It might be nice if they added the feedback on a phrase buttons somewhere in the discussion of that phrase area so then if you realized you should have reported an error, it would be simpler than going back through the material. Maybe i'll suggest it.
My apologies. According to my browser history, when I did the search I accidentally used the wrong kind of quotation marks in one of my queries, thus greatly skewing the results.
I did it all again with more care and it turns out that the article is omitted roughly 60% of the time.
Because this means the comment you replied to was very wrong, I have decided to delete it. Hopefully I haven't misinformed too many people.