Because that is after all the topic of your lecture series.

毕竟这是你们系列讲座的主题。

youdao

Okay, what's the topic of your lecture today?

言归正传，你今天演讲的主题是啥呢？

youdao

Okay, what's the topic of your lecture today?

言归正传，你今天演讲的主题是啥呢？

youdao