他做了一个关于可持续能源的演讲。

He gave a ___talk about sustainable energy.

昨天我参加了一个关于人工智能的精彩讲座。

I attended a fascinating ___talk on artificial intelligence yesterday.

她做了一个关于她艺术家之旅的鼓舞人心的演讲。

She delivered an inspiring ___talk about her journey as an artist.