Another right solutions
A button that shows another right solutions for an exercise could come handy sometimes. It would be great to have one.
The thing is that there are, in average, 500 accepted solutions by Duolingo per sentence (Statistics share by Duo's team), so if you start putting one other, why not 2, 3, 5, 10, 500?...
IMO, it's better that Duo teach one and if you think another one is as much good as the Duo's you can ask native speakers in discussions. Well, it's my opinion.