I was marked wrong for "Audrey adore les mercredis". It wanted "Audrey adore le mercredi". But it appears from the web that both are used, even if the singlar version is more popular.
"J'aime le mercredi" has 232,000 hits
"J'aime les mercredis" has 43,300 hits
So shouldn't this lesson cover the duality and shouldn't the quiz question accept both answers?