That's interesting. I just attended a lecture on pediatric anxiety.

真是巧了，我刚参加了一个关于儿童焦虑症的讲座。

I just attended a lecture on pediatric anxiety.

我刚参加了一个关于儿童焦虑症的讲座。

Before you attend a lecture, it is very important for you to do the reading assignment.

在你参加讲座之前，做阅读作业对你来说非常重要。

Why attend a lecture on a piece of writing that the professor assumes you have read?

为什么要参加教授认为你已经读过的一篇文章的讲座？

If you are free to attend a lecture, but not free to stay away from it, then it is compulsory.

如果你可以自由地参加一个讲座， 但不能自由地远离它， 那么它就是强制性的。