现有应用程序会调用静态服务实现，因此通过引入选择器可以使应用程序变得更灵活。
The existing application invokes a static service implementation, so you will make the application more flexible by introducing a selector.
静态程序库可能引入其自己的新的依赖，而且不容易检查到它们。
A static library can introduce its own new dependencies, and you can't check them as easily.
库装入和卸装引入一些问题，如需要注意静态对象。
Library loading and unloading introduces some issues, such as the need to take care of static objects.
应用推荐