在 + Event/Place + 发言
发言 (fāyán) means "to speak" or "to make a statement," typically in a formal or public setting. It can also function as a noun meaning "a speech" or "remarks." For example, 在会上发言 means "to speak at a meeting."
会议上每个人都有机会发言。
Huìyì shàng měi gè rén dōu yǒu jīhuì fāyán.
Everyone had a chance to speak at the meeting.
总统就这件事发表了公开发言。
Zǒngtǒng jiù zhè jiàn shì fābiǎole gōngkāi fāyán.
The president made a public statement on this matter.
她在发言中提到了教育改革的重要性。
Tā zài fāyán zhōng tídàole jiàoyù gǎigé de zhòngyàoxìng.
In her speech, she mentioned the importance of education reform.