成为 + 话题
话题 (huàtí) means "topic" or "subject of conversation" and refers to what people are talking or writing about. It is commonly used with 成为 (to become) to indicate that something has become a subject of public discussion.
这个话题最近在网上引起了很大的争论。
zhège huàtí zuìjìn zài wǎngshàng yǐnqǐ le hěn dà de zhēnglùn.
This topic has recently sparked a lot of debate online.
大家聊着聊着就换了一个话题。
dàjiā liáozhe liáozhe jiù huàn le yī gè huàtí.
As they chatted, they switched to a different topic.
她的新电影成为了全城最热的话题。
tā de xīn diànyǐng chéngwéi le quán chéng zuì rè de huàtí.
Her new movie became the hottest topic in the whole city.