diff --git a/aio/content/guide/reactive-forms.md b/aio/content/guide/reactive-forms.md
index 9c08299bf4..e2c9c6d8e4 100644
--- a/aio/content/guide/reactive-forms.md
+++ b/aio/content/guide/reactive-forms.md
@@ -1345,20 +1345,30 @@ The remaining `HeroListComponent` and `HeroService` implementation details are b
However, the techniques involved are covered elsewhere in the documentation, including the _Tour of Heroes_
[here](tutorial/toh-pt3 "ToH: Multiple Components") and [here](tutorial/toh-pt4 "ToH: Services").
+`HeroListComponent` 和 `HeroService` 的其它实现细节超出了本教程的范围。
+不过，它所涉及的技术包含在文档的其它部分，包括《英雄指南》的 [这里](tutorial/toh-pt3 "ToH: Multiple Components") 和 [这里](tutorial/toh-pt4 "ToH: Services")。
+
To use the `HeroService`, import it into `AppModule` and add it to the `providers` array. To use the `HeroListComponent`, import it, declare it, and export it:
+要使用 `HeroService`，就要把它导入到 `AppModule` 中，并添加到 `providers` 数组里。
+要使用 `HeroListComponent`，就要导入它、声明它并导出它：
+
Next, update the `HeroListComponent` template with the following:
+接下来，把 `HeroListComponent` 的模板升级为：
+
These changes need to be reflected in the `AppComponent` template. Replace the contents of `app.component.html` with updated markup to use the `HeroListComponent`, instead of the `HeroDetailComponent`:
+这些修改需要反映到 `AppComponent` 模板中。把 `app.component.html` 替换为如下内容，以便把 `HeroDetailComponent` 替换为 `HeroListComponent`：
+
@@ -1366,20 +1376,32 @@ These changes need to be reflected in the `AppComponent` template. Replace the c
Finally, add an `@Input()` property to the `HeroDetailComponent`
so `HeroDetailComponent` can receive the data from `HeroListComponent`. Remember to add the `Input` symbol to the `@angular/core ` `import` statement in the list of JavaScript imports too.
+最后，为 `HeroDetailComponent` 添加一个 `@Input()` 属性，让它能从 `HeroListComponent` 中接收数据。
+别忘了也要把来自 `@angular/core` 的 `Input` 符号 `import` 进来。
+
Now you should be able to click on a button for a hero and a form renders.
+你先，你就可以点击一个按钮并渲染一个表单了。
+
## When to set form model values (`ngOnChanges`)
+## 何时设置表单模型的值（`ngOnChanges`）
+
When to set form model values depends upon when the component gets the data model values.
+何时设置表单模型的值取决于组件何时获得数据模型的值。
+
The `HeroListComponent` displays hero names to the user.
When the user clicks on a hero, the `HeroListComponent` passes the selected hero into the `HeroDetailComponent`
by binding to its `hero` `@Input()` property.
+`HeroListComponent` 会给用户显示英雄的名字。
+当用户点击某个英雄时，`HeroListComponent` 会通过绑定到 `hero` 这个输入属性，把选中的英雄传给 `HeroDetailComponent`。
+
@@ -1389,16 +1411,25 @@ every time the user selects a new hero.
You can call `setValue()` using the [ngOnChanges](guide/lifecycle-hooks#onchanges)
lifecycle hook, which Angular calls whenever the `@Input()` `hero` property changes.
+这种方式下，每当用户选择一个新英雄时，`HeroDetailComponent` 的 `hero` 值就会发生变化。
+你可以通过 [ngOnChanges](guide/lifecycle-hooks#onchanges) 生命周期钩子来调用 `setValue()`。只要 `hero` 这个输入属性发生了变化，Angular 就会调用这个钩子。
+
### Reset the form
+### 重置表单
+
First, import the `OnChanges` symbol in `hero-detail.component.ts`.
+首先，在 `hero-detail.component.ts` 中导入 `OnChanges` 符号。
+
Next, let Angular know that the `HeroDetailComponent` implements `OnChanges`:
+接着，让 Angular 知道 `HeroDetailComponent` 实现了 `OnChanges`：
+
@@ -1414,12 +1445,18 @@ Add the `ngOnChanges` method to the class as follows:
Notice that it calls `rebuildForm()`, which is a method where you
can set the values. You can name `rebuildForm()` anything that makes sense to you. It isn't built into Angular, but is a method you create to effectively leverage the `ngOnChanges` lifecycle hook.
+注意，它调用了 `rebuildForm()`，该函数是一个方法，在这里你可以对值进行设置。
+你可以把 `rebuildForm()` 命名为任何对你有意义的名字。
+它不是 Angular 内置的，而是你自己创建的方法，用以更有效的利用 `ngOnChanges` 钩子。
+
The `rebuildForm()` method does two things; resets the hero's name and the address.
+`rebuildForm()` 方法会做两件事：重置英雄的名字和地址。
+
{@a form-array}
## Use _FormArray_ to present an array of `FormGroups`
@@ -1895,6 +1932,8 @@ Users now can save or revert changes.
Try the .
+试试 .
+
{@a source-code}
The key files of the final version are as follows: