Use abstract fields instead or convert the trait to a class with a constructor.

使用抽象字段，或者把这个trait转换成一个有构造函数的类。

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Code fields may use an abstract set of alphabetic values.

代码字段可能使用字母值的一个抽象集。

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Molecules are more than the sum of their constituent atoms, and they connect with our senses in ways that are much more tangible and diverse than abstract notions of energy, forces and fields.

分子不仅仅是一堆原子的集合，相比能量、力和场等抽象概念，它们以一种更加实体化更加多样化的形式出现在我们面前。

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Leadership and far-sightedness are not general, abstract qualities, but specific to particular tasks and fields and times.

FORBES: The Far-sighted Leader

As I watched more and more games I began to recognize that the little armies of pieces operate like fields of force, and top level games are abstract, deeply nuanced and emotional works of art.

FORBES: Magazine Article