structural features短语¹⁴⁴⁹⁷²⁺² 基本例句 构造细部,结构要点 That denseness makes Tweety's thin little bones surprisingly strong and stiff, good structural features for flight. And thus for keeping those bones from winding up in the mouth of a hungry mammal. 这种密度使翠儿的细瘦骨头惊人地强健坚硬，是飞行的好架子，还能防止被饥饿的哺乳动物给吃掉。 hjenglish