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。

youdao

This conference is another important step initiated by the International Centre on Qanats and Historic Hydraulic Structures (ICQHS) - a category 2 centre under the auspices of UNESCO - to collect and document traditional knowledge available on water resources management from around the globe while providing a forum for presenting new views on the topic.

UNESCO: Water Portal | Water Events Worldwide

Bosniak category IIF cysts are more complex and deserve follow-up imaging to document stability.

CNN: Could my kidney cysts be cancerous?