Why 'we hebben een ambulance nodig' is not correct?! Wij=we (in dutch), right?!
Perhaps he had a listening exercise, and since the pronunciation of "we" and "wij" is different only one will be accepted.
Yes, I had a listening exercise, but the pronunciation of 'we' and 'wij' might sounds the same sometimes. Thank you for your replies.
Both are good, but in the audio, the voice says 'wij', so that's why the only correct answer here is 'wij'. Wij is used to put more emphasis on who's doing it than 'we'. For example in the following conversation, "Gaan we naar huis?" "Ja, wij gaan naar huis, maar zij nog niet."