The English translation of this sentence doesn't appear to make sense. I thought 'petits fruits' meant 'berries' but this was marked wrong. Apparently the correct answer is 'little fruits' but this an unnatural usage that (at least in my experience) would only occur in a metaphorical sense, like for instance, 'low hanging fruits'.
"Berries" is "baies" in French. The problem here is that "fruit" is uncountable in English, so it is rare to say "fruits". In French, "fruit" is countable, so it it normal to say "fruits", just the same as we would say "apples" or "strawberries" or "melons".
If we imagine a person picking out all the small strawberries from a bowl of them, we would probably say "You love eating the little strawberries", or maybe "You love eating the little ones". It's a sentence which is not easy to translate directly, so for us, we just have to accept Duo's translation, but for Duo, I think the solution is to remove the sentence.
It's probably an unfortunate choice of sentence, as I agree that "little fruits" is difficult to imagine, and even "little fruit" is strange, but in French, it sounds more natural. It sounds like "You love to eat the little apples", but of course they can't put every conceivable type of fruit as the English translation!
the female voice at "regular" speeds voices "le petit fruit", but the slow speed voices "les petits fruits". this might be ok if it were a one-off, but it happens all over the website, where one voice is either horrible, or seems to say something different from the other...