13. The distinguishing feature of a fluid, in contrast to a solid, is the ease _____ . (A) that a deformed fluid (B) to deform a fluid (C) when a fluid that is deformed (D) with which a fluid may be deformed 答案: D 分析:整个句子已经有主谓.故后面要加修饰成分.A 的定语从句里没有主谓.B 没有此用法. C 错的原因与A 一样. D 为最佳答案.D 的which 指代ease. 考察:定语从句结构. 参考译文:流体的特征,与固体相比便是流体的形式能被更容易地破坏