on the American Civil War, the book attracted a large number of readers when it was publi

网友回答

(答案→)A. Based
B. Basing
C. Having based
D. Being based
解析：考查形容词用法。本题中考查了更多词组be based on…以…为基础；本题中使用形容词短语based on….对句子的主语the book的情况进行解释；句意：以美国内战为基础，在出版的时候，这本书吸引了很多的读者。故A正确。