DNA转录为RNA过程中所需要的四种原料包括：、、和。
In Willa Cather's first great novel ______________,the heroine Alexandra grows up to make a prosperous farm.
A. O Pioneers !
B. The Song of the Lark
C. My Antonia
D. A Lost Lady
______________ by Katherine Anne Porter tells about the social unrest in Berlin, Germany before World War II.
A. Flowering Judas
B. Pale Horse, Pale Rider
C. The Leaning Tower
D. Ship of Fools
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