why it cant be" they must be our women" in english we can use woman instead of ife
When someone says "ma femme," or "ma fille," it would be safe to assume they're talking about their family... Especially here, where there's usually only one right answer and variations on it.
So what? I don't see where your question is. About the use of "must/have to be"? Imagine a scenario where someone is telling you "I hear female voices talking in the garden", you may answer : "they have to be our wives". What think?
I wasn't really asking a question, I was replying to the person who wanted to know why you can't say woman instead of wife.
OK, I see. that question was about the fact that in this sentence "wife" and "woman" are interchangeable. But "girl/fille" would not work.
So what? A lot of sentences at DuoLingo just don't have any sense at all. I guess we, students, should be aware of any possible translations, regardless how rude they could be.
If you were in a competition against other groups of women, you might say "they must be our women". Woman and wife are the same word in French.