Which measurement of land is equal to 43,560 square feet?

A famous scene from which 1976 film was ad-libbed, as the script simply read "Travis looks in the mirror"? The famous symbol of the Pinkerton Detective Agency is an eye with the slogan "We never..." what? The Marquise de Montespan became the mistress of which French king around 1667? "A Farewell to Arms" and Robert Graves's "Good-Bye to All That" are about which war? A farrow is a litter of which animals? A fascination with brine led which man to found his own chemical company in Michigan in the 1890s? Which fashion designer, born Diane Halfin, is known by the initials DVF? Which fashion footwear mogul has the surname Madden?