下面是2014年5月9日的SAT官方每日一题的内容，是关于阅读方面的，题型是改进句子。SAT官方每日一题是collegeboard每天都会发布的题目，关于SAT考试的三个部分的各个题型。下面我们就一起来看一下这个SAT官方每日一题吧。

　　Part or all of the following sentence is underlined; beneath the sentence are five ways of phrasing the underlined material. Select the option that produces the best sentence. If you think the original phrasing produces a better sentence than any of the alternatives, select choice A.

　　Although biologists have made tremendous progress in mapping the human genome, the genetic roots of most common diseases remained largely elusive.

　　(A) remained

　　(B) had remained

　　(C) remain

　　(D) are remaining

　　(E) remains

　　The correct answer is C

　　Explanation

　　Choice (C) is correct. It avoids the verb tense error of the original. The past tense verb “remained” is not consistent with the present perfect tense verb “have made” and should be changed to the present tense verb “remain.”

　　以上就是关于2014年5月9日的SAT官方每日一题中改进句子的详细内容，包括了题目和选项以及答案，后面附有一道相关的练习题。大家可以在备考SAT的过程中关注SAT每日一题的内容，这样就可以更好有不间断的练习，也就能在日积月累的过程中得到提高。