Which opera, if any,  Venus and Adonis or Bluebeard's Castle has more acts ?
Venus and Adonis (opera) 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.
William Tell (opera) Guillaume Tell (English: William Tell , Italian: Guglielmo Tell ) is a French opera in four acts by Gioachino Rossini to a libretto by Étienne de Jouy and Hippolyte Bis. Based on Friedrich Schiller's play "William Tell," which drew on the William Tell legend, the opera was Rossini's last, although he lived for nearly forty more years. Fabio Luisi said that Rossini planned for "William Tell" to be his last opera even as he composed it. The overture, in four sections and featuring a depiction of a storm as well as a vivacious finale, the "March of the Swiss Soldiers," is often played.