越 + A + 越 + B
The structure 越…越… (yuè…yuè…) links two clauses to express that as one thing increases, another increases in proportion. It conveys the idea of "the more X, the more Y." For example, 越吃越胖 means "the more you eat, the fatter you get."
这本书越看越有意思。
Zhè běn shū yuè kàn yuè yǒu yìsi.
The more you read this book, the more interesting it gets.
雨越下越大,我们还是等一会儿再走吧。
Yǔ yuè xià yuè dà, wǒmen háishi děng yīhuìr zài zǒu ba.
The rain is getting heavier and heavier — let's wait a bit before we go.
她越想越生气,最后决定不去了。
Tā yuè xiǎng yuè shēngqì, zuìhòu juédìng bù qù le.
The more she thought about it, the angrier she got, and in the end she decided not to go.