Other instances in which this pattern is useful include logging and printing, such as when you want only one instance of a class to access and control one particular printer at a time.
Pattern authors can exercise varying degrees of control over deployment by choosing to lock deployment time parameters, ensuring fixed values for every deployment.
模式作者可以尝试对部署进行不同程度的控制，选择锁定部署时间参数，确保为每种部署使用固定的值。
3
In our country, coexistence of various forms of the management control will be the basic feature of management control system pattern in a long period of time.