The classes except for the discovered abstraction class do not have attributes and operations.

除去被发现的抽象类之外，其他类没有属性及操作。

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These abstraction layers give developers the option to use a declarative syntax based on attributes or an imperative model based on nested controls.

这些抽象层让开发人员可选择是使用基于特性标记的声明语法，还是使用基于嵌套控件的命令模型来开发。

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