GMAT句子改错题(sentence correction)，是整个GMAT考试中对考生英语语法能力考查要求最高的题型，也往往是中国学生最为头疼的一类题目。没有扎实的语法基础和一定的逻辑分析能力，想要做好句子改错题难度极高。如何提升GMAT句子改错题的解题能力?下面小编就为大家整理了一些经典例题，结合实例分析为大家讲解GMAT句子改错题的解题思路和方法技巧。
实例题目：
Rock samples taken from the remains of an asteroid about twice the size of the 6-mile-wide asteroid that eradicated the dinosaurs has been dated to be 3.47 billion years old and thus is evidence of the earliest known asteroid impact on Earth.
(A) has been dated to be 3.47 billion years old and thus is
(B) has been dated at 3.47 billion years old and thus
(C) have been dated to be 3.47 billion years old and thus are
(D) have been dated as being 3.47 billion years old and thus
(E) have been dated at 3.47 billion years old and thus are
选项分析：
(A)has been dated to be 3.47 billion years old and thus is
【错误1】主谓一致：“has been dated”和“samples”主谓不一致。
【错误2】固定搭配：不存在“be dated to be”表达“测定年代为”的用法。
(B)has been dated at 3.47 billion years old and thus
【错误】 主谓一致：见(A)中【错误1】。
(C)have been dated to be 3.47 billion years old and thus are
【错误】 固定搭配：见(A)中【错误2】。
(D)have been dated as being 3.47 billion years old and thus
【错误】 固定搭配：不存在“be dated as being”表达“测定年代为”的用法。
(E)have been dated at 3.47 billion years old and thus are
【正确】 “have been dated at 3.47 billion years old”使用了正确的固定搭配。“thus are……”和“have been dated at……”是“Rock samples”的两个对等的谓语动词结构，因此尽管两者外表上不相似(连时态也不相同)，却可以用“and”平行在一起(只要功能一致、概念对等的对象都可以平行)。
【大意】 一个同灭绝恐龙的6英里宽小行星两倍大的小行星上取下的岩石样本测定年代为距今34.7亿年，因此是最早的小行星撞地球的证据。
解题思路：
根据主谓一致原则立即排除(A)、(B)，即便不确定“be dated at”是正确搭配，也可以根据(C)中“to be”表达“目的是”和“将会是”意思不合理，(D)中“as being”的“being”多余故不具有简洁性而选择最优的“be dated at”。因此选择(E)。
