+100 points if anyone ever finds "i'm perfect since i'm black" in any language

That would be a mistranslation. If you take two seconds to look up the definition of feminism it is;
"The advocacy of women's rights on the grounds of political, social, and economic equality to men."
I understand that you were trying to be witty, but it's a pretty old/dumb joke.

Another option for that multiple choice questions was "I want to be in my wife". Pay attention, or you'll miss the truly funny ones.

I was just thinking the same thing: add "car" and "puisque" to the list of words that, even if they're not interchangeable in French, would seem to be synonyms to nonnative learners. While I'm glad that {because/for/since} seem to be interchangeable in the French-English translations, I feel like this program would benefit from additional explanation when we first encounter each of these words.

It's clear that each has its specific use, because they're each relegated to their own types of sentences, but the sentences tend to be wonky enough that I find I'm paying more attention to the strange English grammar than absorbing the differences among these conjunctions, and when I translate English-French, I inevitably pick the wrong since/because.

I guess from comments that Duo doesn't like full form and contracted versions of the same phrase in one sentence. ie: I am and I'm .