1. Read the entire sentence carefully. Try to understand the specific idea or relationship that the sentence should express.(逻辑意思是GMAT考试ETS策略的第一条啊!)
2. Since the part of the sentence that may be incorrect is underlined, concentrate on evaluating the underlined part for errors and possible corrections before reading the answer choices.(错误部分才划线，所以对划线部分格外注意。――虽然实在，但地球人都知道。)
3. Read each answer choice carefully. The first answer choice always repeats the underlined portion of the original sentence. Choose this answer if you think that the sentence is best as it stands, but only after examining all of the other choices.(要看完所有的选项――正确答案是比较出来的)
4. Try to determine how well each choice corrects whatever you consider wrong with the original sentence.(注意正确选项是如何更正原选项的错误的。)
5. Make sure that you evaluate the sentence and the choices in terms of general clarity, grammatical and idiomatic usage, economy and precision of language, and appropriateness of diction.(清晰、符合语法和习惯用法、简洁准确、措词恰当)
6. Read the whole sentence, substituting the choice that you prefer for the underlined part. A choice may be wrong because it does not fit grammatically or structurally with the rest of the sentence. Remember that some sentences will require no corrections. The answer to such a sentence should be the first answer choice.(注意划线之外的部分。)
另外，GMAT攻略大家要注意OG中针对SC说的WHAT IS MEASURED
Sentence correction questions test two broad aspects of language proficiency:
1. Correct expression. A correct sentence is grammatically and structurally sound. It conforms to all the rules of standard written English (for example: non-verb agreement, noun-pronoun agreement, pronoun consistency, pronoun case, and verb tense sequence). Further, a correct sentence will not have dangling, misplaced, or improperly formed modifiers, unidiomatic or inconsistent expressions, or faults in parallel construction.
2. Effective expression. An effective sentence expresses an idea or relationship clearly and concisely as well as grammatically. This does not mean that the choice with the fewest and simplest words is necessarily the best answer. It means that there are no superfluous words or needlessly complicated expressions in the best choice.
In addition, an effective sentence uses proper diction (Diction refers to the standard dictionary meanings of words and the appropriateness of words in context.) In evaluating the diction of a sentence, you must be able to recognize whether the words are well chosen, accurate, and suitable for the context.
This question tests correctness and effectiveness of expression. In choosing your answer, follow the requirements of standard written English; that is, pay attention to grammar, choice of words, and sentence construction. Choose the answer that produces the most effective sentence; this answer should be clear and exact, without awkwardness, ambiguity, redundancy, or grammatical error.