Tā zài zhè suǒ xuéxiào jūgōngjìncuì de jiāoshū sānshí nián.
She devoted herself wholeheartedly to teaching at this school for thirty years.
Tips
history
This idiom is most famously associated with Zhuge Liang (诸葛亮), the brilliant strategist of the Three Kingdoms period. His memorial 出师表 (Chūshī Biǎo) contains the line 鞠躬尽瘁，死而后已 — to give one's all until one's dying breath.
memory
Picture bowing (鞠躬) so deeply you are exhausted (尽瘁). The whole body is spent in service.
