Sorry to interrupt. Shouldn't we get back on topic?

抱歉打断一下，我们是不是该回到正题上？

Not a great song, in my opinion, but bang on topic.

不是一个伟大的歌曲，我的意见，但喋喋不休的话题。

Use your outline to keep your efforts organized and on topic.

使用大纲让您的努力组织和主题。

Course content plan , organize, collect based on topic assigned.

据分配课题计划， 组织， 收集课程内容；

This topic will be the most commented on topic in less than a week.

一周之内这将成为评论最多的话题。