Bonjour,
Réponse :
a. In my latest dream, I was invited by my favourite actor.
b. His new book series is recommended ( by people ).
c. He was taught by his mother to ride a bike.
d. New paintings can be discovered ( by the visitors ) in this exhibition.
Explications :
Passif = BE ( au temps de la voix active ) + participe passé.
Attention :
phrase b "book series" = série de livre / ensemble de livre / collection de livre ==> est un singulier, donc "is recommended" et pas "are recommended"
; )
