澳际留学英语为大家带来了12月12日SAT官方每日一题，今日试题是Writing > Improving Sentences，附带答案解析，希望对SAT备考的同学们有所帮助。
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.
Before she became a major rock star capable of filling stadiums, she sings in little-known clubs and as a back-up singer for other acts.
(B) has sung
(C) is singing
(D) had sung
(E) has been singing