DUO it is still putting interestsmy as one word
Even moderators make typos sometimes. Fixed.
How do I know from the recording that it is books in plural?
Because it is "ces livres", not "ce livre". "Ces" and "ce" are pronounced differently.
how is it different?
Ce = SUH
Ces = SE (as in the e-sound in "ear") or SAY
Why is "these books are of interest to my daughter" wrong?
I think that your answer is correct and should be accepted
My answer should be taken
And your answer was ………..? (fill in the dots)
English version provided is not proper