"Now we are a committee."
Terjemahan:Sekarang kita adalah komite.
Duolingo is not consistent in the use of classifiers and articles.
A classifier (as a replacement for an article) is sometimes required to qualiify for a "good" answer.
Sometimes it's left out.
It does not make any sense.
There are a lot of examples of this and other weird/incorrect/unnatural/literal translations.