fix: typo

aio/content/guide/build.md

@@ -64,7 +64,7 @@ The `build` command uses this as the build target when no environment is specifi
 You can add further variables, either as additional properties on the environment object, or as separate objects. 
 For example, the following adds a default for a variable to the default environment:
 
-当没有制定环境时，`build` 命令就会用它作为构建目标。
+当没有指定环境时，`build` 命令就会用它作为构建目标。
 你可以添加其它变量，可以用该环境对象附加属性的形式，也可以用独立对象的形式。
 比如：以下内容将会把一个变量添加到默认环境中：
 

aio/content/guide/upgrade-performance.md

@@ -310,7 +310,6 @@ A few examples are:
 - You use Angular for a feature that is not critical for the initial rendering of the app and you
   can afford a small delay in favor of better initial load performance.
 
-
   你可以把 Angular 用于应用中那些在初始呈现时不太重要的特性，并且愿意为了更好地初始加载性能，而忍受加载该特性时的一点延迟。
 
 ### Bootstrapping with `downgradeModule()`