French language Q&A Forum

Does avoir besoin de ever become avoir besoin des or du?

Franchir vs croiser always confuses me. Please explain

So the question was:

How would you say ''You haven't lived here long.'' ?

1. Tu n'as pas habité ici depuis longtemps.

2. Tu n'habites pas ici depuis longtemps.

3. Tu n'habitais pas ici depuis longtemps.

4. Tu ne vas pas habiter ici depuis longtemps.

So the instructions are that with negation depuis is in passe composé, so I picked the answer number 1,  but in results this was wrong as they wanted present - answer number 2. 

What gives?

In what part of this sentence could you add "nearly", and what is the word for this? If I said, "My parents have been married for 20 years", or "Mes parents sont mariés il y a vingt ans", how would I say "My parents have been married for nearly 20 years" ? Does this require a different expression entirely? For context, I would be explaining that their wedding anniversary is next month.

"ce sont des filles"

Clearly the nice and better is being used for the boyfriends (subject) and not is the verb, then why on earth are we using mieux here? It seems to be an error, feel free to correct me though.

Si on consulte le site web de l'Académie Française, on voit que aout est aussi correct --> https://www.dictionnaire-academie.fr/article/A9A2062

After submitting my response, no correction page appeared and I was simply presented with the next phrase or sentence.  As a result, I scored zero for my response.  You can't go backwards. This happened twice during the exercise.  On the second occurrence, I was particularly paying attention to not hitting the submit button a second time as I know this can cause skipping.  I could not figure out how to send this to your technical team instead of bothering you.