Which 1937 novel contains the line "A sudden understanding, a pity mixed with horror, welled up in Bilbo's heart"?

Marty Glickman and Sam Stoller, both Jewish, were pulled from the U.S. relay team at the 1936 Summer Olympics in which… 1936 was the last time which team sport on horseback was in the Olympics? The 1936 film "Modern Times" was the last in which which star played his Little Tramp character? 1936's "The Petrified Forest" reteamed Bette Davis with which co-star of "Of Human Bondage"? Who was British prime minister from 1937 to 1940? Which 1937 Best Picture winner is a biography of the writer who defended Alfred Dreyfus? Complete the title of Stephen Vincent Benet's 1937 story: "___ and Daniel Webster". In which 1937 Marx Brothers film does Groucho say, while taking a pulse, "Either he's dead or my watch has stopped"?