I think that should be accepted as an appropriate English translation. It is exactly what the sentence means. Duolingo often seems to fall into the grey hole where the best way to translate is not always clear: translating a phrase literally (word for word) to emphasize the grammar and to understand how the German language and mind work, versus translating the intended meaning of the phrase. Translating the intended meaning is the obvious choice for some very common phrases. Think of "Ich habe Hunger" versus "I am hungry"--Duolingo would never (I think!) offer up "I have hunger" as the correct translation into English. But in other sentences the programmers, monitors, or whoever "they" are seem stuck on literal translations even if those are not the best or most common way to express the idea in English.