[null,null,["最后更新时间 (UTC)：2024-12-21。"],[[["Attachments are content pieces that users interact with within Google Classroom assignments."],["Add-ons facilitate creating and managing attachments, enabling interactive experiences within the platform."],["Two types of add-on attachments exist: \"activity\" for student submissions and \"content\" for view-only materials."],["Activity-type attachments can have grades automatically sent back to Google Classroom, a feature highly valued by educators."],["Add-on attachments can be created programmatically from external sites, similar to creating assignments via API."]]],[]]
