参考答案及解析：

　　1.The correct answer is C

　　Explanation

　　The error in this sentence occurs at (C), where an inappropriate pronoun creates a comma splice. The relative pronoun “which” should be used instead.

　　2.The correct answer is D

　　Explanation

　　The error in this sentence occurs at (D), where there is awkward and wordy phrasing. The conjunction “and” should be either deleted or replaced by “that are.”

　　3.The correct answer is D

　　Explanation

　　The error in this sentence occurs at (D), where there is illogical pronoun use. It doesn’t make sense to say that schools competed against “them” when “them” could refer to “high schools,” “schools,” or even “students.” Instead, “one another” or “each other” is needed.

　　4.The correct answer is B

　　Explanation

　　The error in this sentence occurs at (B), where there is subject-verb disagreement. The singular verb “does” does not agree with the plural noun “processes.” The plural verb “do” is needed instead.

　　以上就是这4道SAT语法句子改错练习题的全部内容，非常详细，后面附有详细的答案解析。大家在备考自己的SAT语法考试的时候，可以加强练习相关题目。