"like a fish out of water"
Translation:kiel fiŝo ekster akvo
Good question! If you think it's too strict, feel free to click the button to report "My answer is also correct", and your suggestion will probably be accepted for future learners.
As for Esperanto, be aware that the use of "la" doesn't necessarily correspond 100% with the use of "the" in English, although it is pretty close. Different speakers might use it a little differently depending on their own background, and Zamenhof himself advised, "If it's too hard, you can just miss 'la' out completely."