Explanation

　　1.The correct answer is B

　　Choice (B) is correct. It avoids the subject-verb agreement error of the original by using the singular verb “sharpens” to agree with the singular subject “Listening.”

　　2.The correct answer is D

　　Choice (D) is correct. It avoids the comma splice error of the original by providing the appropriate modifying phrase “which feeds on the leaves of the mulberry tree.”

　　3.The correct answer is D

　　Choice (D) is correct. It avoids the comma splice error of the original by providing the appropriate modifying phrase “which feeds on the leaves of the mulberry tree.”

　　4.The correct answer is C

　　Choice (C) is correct. It avoids the error of the original by following both parts of the “both … and” construction with the pronoun “his” (“In both his … and his … ”).

　　5.The correct answer is E

　　Choice (E) is correct. It avoids the subject-verb agreement error of the original by replacing the singular verb “was” with the plural verb “were” to agree with the plural subject “All.” It also provides the present participle “including” to avoid any potential ambiguity associated with the relative pronoun “which.”

　　6.The correct answer is E

　　Choice (E) is correct. It avoids the error of the original by placing the appropriate subject (“Barbara Jordan”) immediately after the modifying phrase (“After serving two terms in the Texas State Senate”).