A．Yeats founded the first Irish theater.
B．Yeats stuck to modern forms in his poetry.
C．Yeats began to produce his best works from the age of fifty.
D．Yeats was not favored by the public until the 1923 Noble Prize.
A．Yeats's national honor.
B．Yeats's literary achievements.
C．Yeats's artistic ambition.
D．Yeats's historical influence.
A．Recent fossil evidence connecting whales.
B．Difficulties in the determining the evolutionary history of whales.
C．New discoveries about ancient ancestors of whales.
D．Comparison between whales and other modern-day animals.
A．Similarities between hippopotamus fossils and the whale fossils.
B．Similarities in the genes of hippopotamuses and whales.
C．Similarities in the habitats of hippopotamuses and whales.
D．Similarities in the skeleton structures of hippopotamuses and whales.