fix issue#3

docs/ch12.md

@@ -28,6 +28,8 @@ A sample of specific patterns from Design Patterns will show how a pattern conce
 
 Define a family of algorithms, encapsulate each one, and make them interchangeable. STRATEGY lets the algorithm vary independently from clients that use it. [Gamma et al. 1995]
 
+> 定义了一组算法，将每个算法封装起来，并使它们可以互换。STRATEGY 允许算法独立于使用它的客户而变化。[Gamma et al. 1995]
+
 Domain models contain processes that are not technically motivated but actually meaningful in the problem domain. When alternative processes must be provided, the complexity of choosing the appropriate process combines with the complexity of the multiple processes themselves, and things get out of hand.
 
 > 领域模型包含一些并非用于解决技术问题的过程，将它们包含进来是因为它们对处理问题领域具有实际的价值。当必须从多个过程中进行选择时，选择的复杂性再加上多个过程本身的复杂性会使局面失去控制。