Translation:We will arrive in the city in two hours.
As an English native, I think at is acceptable to use 'at'. Maybe there is some forgotten piece of grammatical law stating that it's incorrect, I do not know. But I speak fairly well, at I would use 'at' more often than 'in'.
I disagree, both are correct- You can be said to arrive AT a place. IN a place is correct if you're already there, or in a specific structure, but regardless, "I'm at the library" is synonymous with "I'm in the library", and nobody arrives in or into anywhere.
I never said Duo's answer is wrong, what I'm saying is that my answer is correct as well, at least in English.
I saw the link. It does not say that my answer is wrong, rather it says that Duo's answer is right: Which, as I said, I have no problem with.
So no, I continue to contend that my answer is right, especially since the point of language is to convey meaning: If someone says to me that they have arrived in or at a city I'm hardly going to stop to tell them that they're wrong about their preposition use, I'm going to be more concerned with wherever it is they've arrived at after all
Both are synonymous in written, spoken, colloquial and idiomatic English and among the many synonymic translations Duo accepts, my answer should be one of them.
Yeah, I just did this one again. It's wayyy more natural for new to say "at" here rather than "in". Emeyr's assertion above that "in" is the only acceptable preposition with the verb "arrive" is just completely incorrect.