anchor.diff:  
     While building out the crisis center feature, you navigated to the
     crisis detail route using an **absolute path** that begins with a _slash_.
  +  
  +  虽然构建出了危机中心特性区，我们却仍在使用以斜杠开头的**绝对路径**来导航到危机详情的路由。
   
     The router matches such _absolute_ paths to routes starting from the top of the route configuration. 
  +  
  +  路由器会从路由配置的顶层来匹配像这样的*绝对路径*。
   
     You could continue to use absolute paths like this to navigate inside the *Crisis Center*
     feature, but that pins the links to the parent routing structure. 
     If you changed the parent `/crisis-center` path, you would have to change the link parameters array.
  +  
  +  我们固然可以继续像*危机中心*特性区一样使用绝对路径，但是那样会把链接钉死在特定的父路由结构上。
  +  如果我们修改了父路径`/crisis-center`，那就不得不修改每一个链接参数数组。
   
     You can free the links from this dependency by defining paths that are **relative** to the current URL segment.
     Navigation _within_ the feature area remains intact even if you change the parent route path to the feature.
  +  
  +  通过改成定义*相对于*当前URL的路径，我们可以把链接从这种依赖中解放出来。
  +  当我们修改了该特性区的父路由路径时，该特性区*内部*的导航仍然完好无损。
   
     Here's an example:
  +  
  +  例子如下：
   
   .l-sub-section
     :marked
       The router supports directory-like syntax in a _link parameters list_ to help guide route name lookup:
  +    
  +    在*链接参数数组*中，路由器支持"目录式"语法来指导我们如何查询路由名：
   
       `./` or `no leading slash` is relative to the current level.
  +    
  +    `./`或`无前导斜线`形式是相对于当前级别的。
   
       `../` to go up one level in the route path.
  +    
  +    `../`会回到当前路由路径的上一级。
   
       You can combine relative navigation syntax with an ancestor path. 
       If you must navigate to a sibling route, you could use the `../<sibling>` convention to go up
       one level, then over and down the sibling route path.
  +    
  +    我们可以把相对导航语法和一个祖先路径组合起来用。
  +    如果不得不导航到一个兄弟路由，我们可以用`../<sibling>`来回到上一级，然后进入兄弟路由路径中。
   
   :marked
     To navigate a relative path with the `Router.navigate` method, you must supply the `ActivatedRoute`
     to give the router knowledge of where you are in the current route tree. 
     
  +  用`Router.navigate`方法导航到相对路径时，我们必须提供当前的`ActivatedRoute`，来让路由器知道我们现在位于路由树中的什么位置。
  +  
     After the _link parameters array_, add an object with a `relativeTo` property set to the `ActivatedRoute`.
     The router then calculates the target URL based on the active route's location.
  -
  -  “重定向（redirect）路由”需要一个`pathMatch`属性来告诉路由器如何把URL和路由中的路径进行匹配。
  -  本应用中，路由器应该只有在*完整的URL*匹配`''`时才选择指向`CrisisListComponent`的路由，因此，我们把`pathMatch`的值设置为`'full'`。
  +  
  +  在*链接参数数组*中，添加一个带有`relativeTo`属性的对象，并把它设置为当前的`ActivatedRoute`。
  +  这样路由器就会基于当前激活路由的位置来计算出目标URL。
   
   .l-sub-section
   
     :marked
       **Always** specify the complete _absolute_ path when calling router's `navigateByUrl` method.
  +    
  +    当调用路由器的`navigateByUrl`时，**总是**要指定完整的*绝对路径*。
   
   a#nav-to-crisis
   :marked
  
positive.code:     
      只在根模块`AppRoutingModule`中调用`RouterModule.forRoot`（如果在`AppModule`中注册应用的顶级路由，那就在`AppModule`中调用）。
      在其它模块中，我们就必须调用**`RouterModule.forChild`**方法来注册附属路由。
      
  a#adding-routing-module
  :marked
    ### Add the routing module to the _HeroesModule_
  
negative.code:   The absolute URL for the latter example, including the `localhost` origin, is
  
    本例子中包含站点部分的绝对URL，就是：
  
  code-example.
    localhost:3000/crisis-center/2
  
  