1·Once subscribed to a topic, all messages that are published on that topic will be sent to the subscriber.
一旦订阅了主题，就将根据此主题发布的所有消息发送到订阅服务器。
2·Subscription-based notifications, which are system messages alerting users of information events to which they have subscribed.
基于订阅的通知，它是系统消息，负责向用户通知他们所订阅的信息事件。
3·Then, you learned how to add a subscription feature so we can notify our users by email when new documents are added to the document category to which they are subscribed.
然后，学习了如何添加订阅特性，这样当用户订阅的文档类别中添加了新文档时，我们就可以通过电子邮件通知他们。
4·The event channel deals with event hierarchies by determining the most specific subtype of the event interface subscribed by an event receiver.
事件通道通过确定事件接收者订阅的事件接口的最具体的子类型，来处理事件层次结构。
5·The version from Part 1 pulls data from the subscribed services each time the page is requested.
第1部分的版本将在每次请求页面时从订阅的服务中提取数据。