参考答案及解析：

　　1.The correct answer is D

　　Explanation

　　Choice (D) is correct. It avoids the comma splice error of the original by combining the two independent clauses that were improperly joined by only a comma (“There are many famous quotations previously credited to ‘Anonymous’” and “researchers have discovered that they were in fact written by female authors”) into one sentence consisting of a main clause (“Researchers have discovered”) and a dependent clause (“that many famous quotations previously credited to ‘Anonymous’ were in fact written by female authors”).

　　2.The correct answer is A

　　Explanation

　　Choice (A) is correct. It avoids the errors of the other options by using the idiomatic “as” to complete the phrase “as much … as.”

　　3.The correct answer is B

　　Explanation

　　Choice (B) is correct. It avoids the error of the original by linking the subject of the sentence, “origami,” with an appropriate verb form, “seems to have developed.”

　　4.The correct answer is C

　　Explanation

　　Choice (C) is correct. It avoids the error of the original by using the pronoun “his” to indicate that the “controversial paintings” discussed in the sentence were produced by de Kooning.

　　5.The correct answer is D

　　Explanation

　　Choice (D) is correct. It avoids the unidiomatic phrasing of the original by linking an appropriate prepositional phrase, “with bringing,” to the verb “credited.”

　　6.The correct answer is B

　　Explanation

　　Choice (B) is correct. It avoids the subject-verb agreement error of the original by providing a singular verb, “involves,” for the singular subject, “Reading.”