答案：C

题目分析：动词短语辨析。A.died from死于外因或某种不明原因其后常跟wound， accident, over work, carelessness, drinking 等名词B.died off相继死去C. died away尤指（声音、光、风）逐渐消失，停止；昏厥；自行消失D. died out灭绝。句意：直到汽车的声音逐渐消失，我才能再听节目。故选C

点评：动词短语是高考题中常考的内容，平时要多积累，运用，掌握好它们的基本含义，学会总结动词短语的规律，对于有些短语意义很接近, 这要结合例句和上下文掌握它们的用法。