Bull elephants rarely fight, but bulls of which "elephant" marine mammal often battle it out for mates?

Begun under Ptolemy I in the 3rd century BC, which institution was the greatest library of the ancient world? Built on landfill, San Francisco's Marina District was one of the areas hardest hit by which 1989 event? Built to hold 10,000 prisoners, which Confederate prison camp in Georgia often held about three times that number? Bulgaria's "Mila Rodino", which means "Dear Homeland", is its national what? "Bullet Bob", a pitcher from Van Meter, Iowa, joined the Cleveland Indians at age 17 in 1936. Who was he? Bumble Bee sells cans of which pink fish from Alaska? Bumblebee Man, Kent Brockman and Dr. Nick Riviera are characters on which animated series? Bunny Austin shocked the tennis world when he wore what at Forest Hills in 1932?