Which broadcaster co-hosted ABC's "20/20" with Barbara Walters for many years?

Barbara Mikulski, Elizabeth Dole and Barbara Boxer all served in which legislative body? Barbara Stanwyck earned an Oscar nomination for which 1948 thriller based on a 1943 radio play? Barbara Stanwyck won an Emmy for her work in which 1983 TV miniseries? Barbara Tuchman won a Pulitzer Prize for "The Guns of August," a history of the first month of which war? Barbara Walters started as a writer on which NBC morning show in 1961 and eventually became its first female co-host? Racehorses Barbaro and Seattle Slew and the zebra all belong to which genus? Frederick Barbarossa led an army in which Crusade, which began in 1189 and lasted until 1192? Barbie dolls, credit cards and the keys of modern pianos are commonly made of what material?