French language Q&A Forum

A multiple choice question I got gave me the options of (1) “La porte fait un mètre de large.”, (2) “La porte a un mètre de large.”, (3) “La porte est un mètre de largeur.”, (4) “La porte est large d'un mètre.”. According to the dictionary I use, you can use avoir, too, and it gives the example of “Ce meuble a 45 cm de large.”; however, the quizz insists only (1) and (4) are correct. Who’s right?

Per the given definition of the use of demeurer, je suis demeurê makes no sense since the question refers to a state of mind and not a location. Why is that given as the correct answer?

Nous avons visité une exposition qu'un ami a recommandée.

If 'que' referred to 'un musée', then the past participle would lack the final 'e'?

I find the difference between singular and plural to be very subtle in spoken French, even when spoken slowly and carefully as in the audio lessons.

des (¨day¨) vs de (¨duh¨) 

J'adore aussi l'odeur des châtaignes (plural)

J'adore aussi l'odeur de châtaigne (singular)

Any hints on how to pick up that difference when listening?