Which opera, if any,  Venus and Adonis or Bluebeard's Castle has more acts ?
Venus and Adonis
Title: Venus and Adonis (opera)
Passage: Venus and Adonis is an opera in three acts and a prologue by the English Baroque composer John Blow, composed in about 1683.  It was written for the court of King Charles II at either London or Windsor.  It is considered by some to be either a semi-opera or a masque, but "The New Grove" names it as the earliest known English opera.
Title: The Death of Adonis (Rubens)
Passage: The Death of Adonis is a c.1614 painting by Peter Paul Rubens, now in the Israel Museum in Jerusalem.  It shows the dead Adonis being mourned by Venus, Cupid and the Three Graces
Title: Bluebeard's Castle
Passage: Bluebeard's Castle (Hungarian: A kékszakállú herceg vára ; literally: "The Blue-Bearded Duke's Castle") is a one-act opera by Hungarian composer Béla Bartók.  The libretto was written by Béla Balázs, a poet and friend of the composer, and is written in Hungarian, based on the French literary tale "La Barbe bleue" by Charles Perrault.  The opera lasts only a little over an hour and there are only two singing characters onstage: Bluebeard ("Kékszakállú "), and his new wife Judith ("Judit " ); the two have just eloped and Judith is coming home to Bluebeard's castle for the first time.
Venus and Adonis (opera) Bluebeard's Castle